Fingerprint sensing display apparatus

ABSTRACT

A display display is disclosed. The display device comprises a substrate and a transistor on the substrate. An electroluminescence element is on the transistor and an encapsulation unit is on the electroluminescence element. A fingerprint sensor is under the second surface of the substrate. A portion of the substrate, a portion of the transistor, a portion of the electroluminescence element, and a portion of the encapsulation unit that overlap the fingerprint sensor are an ultrasonic transmission and reception channel on the fingerprint sensor.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority of Republic of Korea PatentApplication No. 10-2017-0180788 filed on Dec. 27, 2017, in the KoreanIntellectual Property Office, the disclosure of which is incorporated byreference in its entirety.

BACKGROUND Technical Field

The present disclosure relates to a display device capable offingerprint recognition. Specifically, the display device is capable ofrecognizing a fingerprint using an ultrasonic technique by placing anultrasonic fingerprint sensor under the rear surface of anelectroluminescence display panel such that the electroluminescencedisplay panel becomes a transmission and reception channel of theultrasonic signal.

Related Technology

Referring to FIG. 1, a conventional fingerprint sensor 14 is attached tothe periphery of the liquid crystal display panel 11 of the conventionaldisplay device 10 to support a fingerprint recognition function. Theconventional display device 10 includes a liquid crystal display panel11, a fingerprint sensor 14 disposed around the liquid crystal displaypanel 11 so as to be exposed to the environment, a first speaker 12 anda second speaker 13. It has been difficult to make the conventionaldisplay device 10 with a narrow bezel due to the fingerprint sensor 14and the speakers 12 and 13. Therefore, it has been difficult to increasethe display area ratio of the display panel 11 of the display device 10.

SUMMARY

The present disclosure describes an electroluminescence display panelcapable of displaying a superior image quality. The electroluminescencedisplay panel includes an electroluminescence element.

In particular, an ultrasonic sensor is disposed under the rear surfaceof the electroluminescence display panel. The electroluminescencedisplay panel may include an organic light emitting diode (OLED) and/ora quantum-dot light emitting diode (QLED).

By placing a fingerprint sensor under the rear surface of anelectroluminescence display panel, a fingerprint recognition functioncan be provided by touching a user finger on a display area or a coverglass on a display area through an electroluminescence display panel.Further, in such case, a width of the bezel of the display deviceincluding the electroluminescence display panel can be minimized,thereby maximizing the area of the electroluminescence display panel ofthe display device.

Further, an ultrasonic signal can be used for recognizing a fingerprintthrough an electroluminescence display panel, and sensitivity of theultrasonic signal may be reduced for various reasons. In addition, whenthe sensitivity of the ultrasonic signal reduced, the recognitionsuccess rate may be lowered, and the fingerprint recognition speed maybe lowered, so that the user may experience a slow response speed.

In order to perform fingerprint recognition through anelectroluminescence display panel, the frequency of the ultrasonicsignal of the fingerprint sensor may be at least 10 MHz and if thefrequency of the ultrasonic signal is in such a high frequency band, thesensitivity of the ultrasonic signal can be reduced according to thedensity or the Young's Modulus of the respective elements, and/orthickness of the respective elements.

An image quality of the electroluminescence display panel and/or thesensitivity of the fingerprint sensor may be degraded due toelectromagnetic interference (EMI) generated between the fingerprintsensor and the electroluminescence display panel.

When the fingerprint sensor is attached to the electroluminescencedisplay panel, the flatness of the substrate of the electroluminescencedisplay panel may be deteriorated by the stress applied to the substrateof the electroluminescence display panel by the fingerprint sensor.Accordingly, a pressed mark of the electroluminescence display panel maybe visible.

When the fingerprint sensor is disposed on the rear surface of theelectroluminescence display panel, the light-shielding level at the rearsurface of the electroluminescence display panel may vary according tothe fingerprint sensor arrangement. Thus, the characteristics of thedisplay panel may be varied accordingly. Therefore, a stain defect, forexample, a shadow-mura may occur.

When the fingerprint sensor is disposed on the rear surface of theelectroluminescence display panel, the heat radiation characteristic ofthe rear surface of the electroluminescence display panel may varyaccording to the arrangement of the fingerprint sensor and an imageretention may be generated in a displayed image due to the temperaturedeviation of the electroluminescence display panel.

Accordingly, it is an object of the present disclosure to provide astructure of a display device capable of improving above-mentionedproblems, in which an ultrasonic fingerprint sensor disposed on the rearsurface of an electroluminescence display panel.

Accordingly, an object of the present disclosure is to provide astructure of a display device capable of overcoming the above-mentionedproblems and improving various problems that may degrade the imagequality of the electroluminescence display panel, thereby improving thesensitivity of the ultrasonic sensor signal and improving the speed offingerprint recognition.

In one embodiment, a display device comprises: a substrate including afirst surface and a second surface that is under the first surface; atransistor on the first surface of the substrate; an electroluminescenceelement on the transistor; an encapsulation unit on theelectroluminescence element; and a fingerprint sensor under the secondsurface of the substrate; wherein a portion of the substrate, a portionof the transistor, a portion of the electroluminescence element, and aportion of the encapsulation unit that overlap the fingerprint sensorare an ultrasonic transmission and reception channel on the fingerprintsensor.

In one embodiment, a display device comprises: a substrate including afirst surface and a second surface that is under the first surface; anultrasonic fingerprint sensor on a portion of the second surface of thesubstrate; an adhesive between the substrate and the ultrasonicfingerprint sensor, the adhesive in direct contact with the ultrasonicfingerprint sensor; a transistor including an insulating unit, thetransistor on the first surface of the substrate, and wherein an air gapis not present between the transistor and the substrate; a planarizationlayer directly on the transistor; an electroluminescence elementdirectly on the planarization layer; and an encapsulation unit includinga plurality of encapsulation layers, the encapsulation unit directly onthe electroluminescence element, and wherein the plurality ofencapsulation layers lack an air gap between the plurality ofencapsulation layers.

In one embodiment, a display device comprises: a display panelcomprising a plurality of components; an ultrasonic fingerprint sensorunder a portion of the display panel; and a first adhesive that attachesthe ultrasonic fingerprint sensor directly to the display panel; whereineach of the plurality of components in a portion of the display panelthat horizontally overlaps the ultrasonic fingerprint sensor is incontact with at least one other component from the plurality ofcomponents of the display panel.

It should be noted that the objects of the present disclosure are notlimited to those described above and other objects of the presentdisclosure included in the following descriptions can be clearlyunderstood by those skilled in the art from the following description.

It should be noted that the effects of the present disclosure are notlimited to those described above and other effects of the presentdisclosure are included in the following descriptions.

BRIEF DESCRIPTION OF DRAWINGS

The above and other aspects, features and other advantages of thepresent disclosure will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 explains a conventional display device;

FIG. 2 is a conceptual diagram schematically illustrating a displaydevice capable of providing a fingerprint recognition function accordingto an embodiment of the present disclosure;

FIG. 3 is a plan view schematically illustrating an electroluminescencedisplay panel of a display device capable of providing a fingerprintrecognition function according to an embodiment of the presentdisclosure;

FIG. 4 is a cross-sectional view schematically illustrating a crosssection A′-A″ of the display device as illustrated in FIG. 3 accordingto an embodiment of the present disclosure;

FIG. 5 is a cross-sectional view illustrating a stack structure of anexemplary electroluminescence display panel which can be applied to across-section A′-A″ of a display device schematically illustrated inFIG. 4 according to an embodiment of the present disclosure;

FIG. 6 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to anotherembodiment of the present disclosure;

FIG. 7 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 8 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 9 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 10 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 11 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 12 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 13 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 14 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 15 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 16 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 17 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 18 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 19 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 20 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 21 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 22 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 23 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 24 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 25 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 26 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 27 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 28 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 29 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 30 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 31 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 32 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 33 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 34 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 35 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 36 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure;

FIG. 37 is a conceptual diagram schematically illustrating a displaydevice capable of providing a fingerprint recognition function, apressure sensing function, and a speaker function according to the otherembodiment of the present disclosure;

FIG. 38 is a plan view schematically illustrating an electroluminescencedisplay panel of a display device capable of providing a fingerprintrecognition function, a pressure sensing function, and a speakerfunction according to the other embodiment of the present disclosure;

FIGS. 39A, 39B, and 39C are cross-sectional views schematicallyillustrating a cross section B′-B″ corresponding to a fingerprintrecognition area of a display device including an electroluminescencedisplay panel capable of providing a fingerprint recognition function, apressure sensing function, and a speaker function according to the otherembodiment of the present disclosure;

FIGS. 40A, 40B, and 40C are cross-sectional views schematicallyillustrating a cross section C′-C″ corresponding to a fingerprintrecognition area of a display device including an electroluminescencedisplay panel capable of providing a fingerprint recognition function, apressure sensing function, and a speaker function according to the otherembodiment of the present disclosure;

FIGS. 41A, 40B, and 40C are cross-sectional views schematicallyillustrating a cross section D′-D″ corresponding to a fingerprintrecognition area of a display device including an electroluminescencedisplay panel capable of providing a fingerprint recognition function, apressure sensing function, and a speaker function according to the otherembodiment of the present disclosure;

FIG. 42 is a cross-sectional view illustrating a stack structure of anexemplary electroluminescence display panel which can be applied to across-section A′-A″ of a display device according to the otherembodiment of the present disclosure.

DETAILED DESCRIPTION

Advantages and characteristics of the present disclosure and a method ofachieving the advantages and characteristics will be clear by referringto the embodiments described below in detail together with theaccompanying drawings. However, the present disclosure is not limited tothe embodiment disclosed herein but will be implemented in variousforms. The embodiments are provided by way of example only so that aperson of ordinary skilled in the art can fully understand thedisclosures of the present disclosure and the scope of the presentdisclosure. Therefore, the present disclosure will be defined only bythe scope of the appended claims.

The shapes, sizes, ratios, angles, numbers, and the like illustrated inthe accompanying drawings for describing the various embodiments of thepresent disclosure are merely examples, and the present disclosure isnot limited thereto. Like reference numerals generally denote likeelements throughout the specification. Further, in the followingdescription of the present disclosure, a detailed explanation of knownrelated technologies may be omitted to avoid unnecessarily obscuring thesubject matter of the present disclosure. The terms such as “including”,“having” and “comprising” used herein are generally intended to allowother components to be added unless the terms are used with the term“only”. Any references to singular may include plural unless expresslystated otherwise.

Components are interpreted to include an ordinary error range (e.g., atolerance range) even if not expressly stated.

When the position relation between two parts is described using theterms such as “on”, “above”, “below”, and “next”, one or more parts maybe positioned between the two parts unless the terms are used with theterm “immediately” or “directly”.

When an element or layer is disposed “on” other element or layer,another layer or another element may be interposed directly on the otherelement or therebetween.

If it is described that a component is “connected” or “coupled” toanother component, it is understood that the component is directlyconnected or coupled to the other component but another component may be“connected” or “coupled” between the components.

Although the terms “first”, “second” and the like are used fordescribing various components, these components are not confined bythese terms. These terms are merely used for distinguishing onecomponent from the other components. Therefore, a first component to bementioned below may be a second component in a technical concept of thepresent disclosure.

Like reference numerals refer to like elements throughout thespecification.

A size and a thickness of each component illustrated in the drawing areillustrated for convenience of description, and the present disclosureis not limited to the size and the thickness of the componentillustrated.

Each of the features of the various embodiments of the presentdisclosure can be combined or combined with each other partly orentirely. Those skilled in the art will understand that the features ofthe various embodiments can be technically interlocked and driven aswell. The features of the various embodiments can be practicedindependently or in conjunction with each other independently of eachother.

Hereinafter, various embodiments of the present disclosure will bedescribed in detail with reference to accompanying drawings.

FIG. 2 is a conceptual diagram schematically illustrating a displaydevice capable of providing a fingerprint recognition function accordingto an embodiment of the present disclosure.

Referring to FIG. 2, a display device 100 according to an embodiment ofthe present disclosure will be described.

The display device 100 according to an embodiment of the presentdisclosure may include an electroluminescence display panel 110 and acase supporting the electroluminescence display panel 110.

Various components may be placed inside the case of the display device100. For example, speakers 12, 13 (e.g., a first speaker 12 and a secondspeaker 13), a battery, a printed circuit board, an antenna, a sensor,and/or a camera may be disposed. However, the present disclosure is notlimited thereto.

The electroluminescence display panel 110 is configured to include afingerprint recognition area (FDA) configured to recognize or to detecta fingerprint of a finger that is touched when a user's finger touches aspecific area of the electroluminescence display panel 110. Accordingly,the display device 100 according to an embodiment of the presentdisclosure can recognize a fingerprint by inputting a touch to theelectroluminescence display panel 110. Thus, the fingerprint recognitionarea FDA may refer to a particular area of the electroluminescencedisplay panel 110 configured to detect the fingerprint. According to theembodiments of the disclosure, the fingerprint recognition area FDA maybe located at one or a plurality of different positions of theelectroluminescence display panel 110 as well as the area correspondingto the home button as illustrated in FIG. 1.

Therefore, the display device 100 (i.e., the apparatus) can detect thefingerprint through the electroluminescence display panel 110 and mayprovide various security functions. Since a separate fingerprint sensorcan be omitted from the bezel area of the display device 100, thedisplay area ratio of the electroluminescence display panel 110 in thedisplay device 100 can be maximized.

For convenience of explanation, the ultrasonic fingerprint sensor of theultrasonic type will be referred to as a fingerprint sensor.

Various user interfaces (UI) corresponding to the fingerprintrecognition operation may be displayed in the fingerprint recognitionarea FDA through a plurality of pixels.

For example, for a short message service (SMS) reception notificationwindow, the fingerprint recognition function may be activated such thata fingerprint recognition position may be displayed for a user and aguidance message for finger contact may be displayed. The fingerprintrecognition process can be performed to support various userauthentication functions, and it can be applied to functions such assecurity access, online payment, and user registration. If a pluralityof fingerprint sensors is placed at various positions of theelectroluminescence display panel 110, different functions may beprovided for each fingerprint recognition position.

FIG. 3 is a plan view schematically illustrating an electroluminescencedisplay panel of a display device capable of providing a fingerprintrecognition function according to an embodiment of the presentdisclosure.

Referring to FIG. 3, an electroluminescence display panel 110 of thedisplay device 100 according to an embodiment of the present disclosurewill be described.

The electroluminescence display panel 110 according to an embodiment ofthe present invention may be configured to include a plurality of pixelsPXL. The region where the plurality of pixels PXL is arranged may bedefined as a display area AA. The area other than the display area AA orthe peripheral area of the display area AA may be defined as thenon-display area NA.

In the non-display area NA, a driving unit for driving the plurality ofpixels PXL is disposed. The driving unit may include a gate driver forsupplying a scan signal to the switching transistor of the pixel PXL anda data driver for supplying a video signal to the data line.

The pixel PXL of the electroluminescence display panel 110 may includean electroluminescence element that displays a specific color. Forexample, the pixel PXL may be configured to include red, green, and blueelectroluminescence elements, or may be configured to include red,green, blue, and white electroluminescence elements, or may beconfigured to include red, green, blue, and green electroluminescenceelements.

The pixel PXL may include at least a switching transistor, a drivingtransistor, and a storage capacitor.

The switching transistor is turned on when a scan signal is supplied tothe scan line, and supplies the data signal supplied to the data line tothe gate electrode of the driving transistor and the storage capacitor.

The driving transistor controls the current supplied to theelectroluminescence element according to the data signal, which is avideo signal supplied to the gate electrode of the driving transistor,and a high potential voltage supplied from a high potential power supplyline, thereby controlling the brightness of light emitted from theelectroluminescence element. Even if the switching transistor is turnedoff, the driving transistor may supply the current until the data signalof the next frame is supplied by the potential difference charged in thestorage capacitor, so that the electroluminescence element may maintainthe light emission. The electroluminescence element may be anelectroluminescence diode, and the electroluminescence diode may includean anode electrode, an electroluminescence layer corresponding to theanode electrode, and a cathode electrode corresponding to theelectroluminescence layer. The cathode electrode may be configured toreceive a low potential voltage from a low potential power supply line.

Ultrasonic waves generated from the fingerprint sensor are transmittedto the fingerprint recognition area FDA set in the display area AA. Thefingerprint sensor may be configured to detect a fingerprint by sensingultrasonic waves reflected from the finger.

FIG. 4 is a cross-sectional view schematically illustrating a crosssection A′-A″ of the display device as illustrated in FIG. 3 accordingto one embodiment.

Referring to FIG. 4, the electroluminescence display panel 110 and thefingerprint sensor 140 of the display device 100 according to anembodiment of the present disclosure will be described.

In one embodiment, the electroluminescence display panel 110 comprises afirst surface (e.g., a front side) and a second surface (e.g., a rearside) that is opposite the first surface. As shown in FIG. 4, generally,the first surface is touched by a finger of a user. A fingerprint sensor140 is positioned under the rear side (e.g., the second surface) of theelectroluminescence display panel 110 of the display device 100according to an embodiment of the present disclosure.

The fingerprint sensor 140 may be used for approval function, throughthe display area AA by the ultrasonic wave technique, for the user. Thefingerprint sensor 140 may generate ultrasonic waves and the generatedultrasonic waves may be transmitted toward the electroluminescencedisplay panel 110. The fingerprint sensor 140 may be configured todetect the ultrasonic waves transmitted through the electroluminescencedisplay panel 110, reflected by the finger, and then received by thefingerprint sensor 140 through the electroluminescence display panel110. The fingerprint sensor 140 may be configured to analyze a sensedultrasonic signal to generate an ultrasonic image to determine afingerprint.

The characteristics of ultrasonic waves for fingerprint recognition usedin the fingerprint sensor 140 of the display device 100 according to anembodiment of the present disclosure will be described.

In the case of ultrasonic waves, as the frequency increases, the degreeof signal attenuation increases rapidly in low-density materials.Therefore, as the frequency increases, the density of the transmissionand reception channel of the ultrasonic wave greatly affects the qualityof the ultrasonic signal. To improve the quality of the ultrasonicsignal, in one embodiment, the Young's modulus of the correspondingmediums between a user's finger and the fingerprint sensor 140 withinthe transmission and reception channel have matching acoustic impedancecharacteristics. When an ultrasonic signal is emitted toward stackedmediums with matching acoustic impedances, there is less ultrasonicsignal reflection at the interface of different mediums compared to whenthe stacked mediums have mismatched acoustic impedances. That is, whenthe ultrasonic waves enter from one medium into another medium and theacoustic impedances between the two mediums match, a reflectance of theultrasonic waves at a boundary between the mediums is reduced.Accordingly, a transmittance of the ultrasonic waves to a next medium isincreased.

In the case of an ultrasonic image for fingerprint recognition, theresolution of the ultrasonic image increases as the frequency increases.Ultrasonic fingerprint recognition technology requires a level ofultrasonic image resolution that can detect the fingerprint valley.

The fingerprint sensor 140 disposed under the rear surface of theelectroluminescence display panel 110 of the display device 100according to an embodiment of the present disclosure may be configuredto receive and transmit a frequency of at least 10 MHz or more torecognize a fingerprint. According to the above-described configuration,the fingerprint can be recognized by using the electroluminescencedisplay panel 110 as a channel for ultrasonic transmission andreception.

The fingerprint sensor 140 disposed under the rear surface of theelectroluminescence display panel 110 of the display device 100according to an embodiment of the present disclosure may be configuredto receive and transmit a frequency of 15 MHz or less to recognize afingerprint. If a frequency of 15 MHz or more is used, the level ofultrasonic wave signal attenuation can be significant, and signalsensitivity may be reduced when the electroluminescence display panel isused as a transmission and reception channel.

FIG. 5 is a cross-sectional view illustrating a stack structure of anexemplary electroluminescence display panel which can be applied to across-section A′-A″ of a display device schematically illustrated inFIG. 4.

Referring to FIG. 5, an electroluminescence display panel 110 accordingto an embodiment of the present disclosure will be described. Theelectroluminescence display panel 110 as illustrated in FIG. 5 is merelyan example, and various modifications with respect to the stackingstructure, stacking order, thickness, and density of each element of theelectroluminescence display panel 110 may be made without departing fromthe technical scope of the present disclosure.

The display device 100 according to an embodiment of the presentdisclosure may be configured to include an electroluminescence displaypanel 110 and a fingerprint sensor 140 under the rear side of theelectroluminescence display panel 110.

The fingerprint sensor 140 may generate ultrasonic waves. The ultrasonicwaves generated by the fingerprint sensor 140 may pass through theelectroluminescence display panel 110 and may detect the densitydifference of the air portion within the fingerprint valley and the skinof the fingerprint. As an example, the fingerprint sensor 140 may beconfigured to include a sensor substrate 142, transmitting (Tx)electrodes 141 and receiving (Rx) electrodes 143 on the sensor substrate142, a Tx/Rx layer 144 on the Tx electrodes 141 and Rx electrodes 143,and a cover substrate 146 on the Tx/Rx layer 144. However, the presentdisclosure is not limited thereto.

Generally, the fingerprint sensor 140 obtains an image of a fingerprintby measuring the difference in density between fingerprint ridges (skin)and fingerprint valleys (air). Specifically, The Tx electrodes 141 maybe configured to output ultrasonic waves to a finger, and the Rxelectrodes 143 may be configured to sense ultrasonic waves reflectedfrom the finger. Accordingly, the fingerprint sensor 140 may be definedas an electrode structure configured to transmit and receive ultrasonicwaves. An advantage of using ultrasonic technology to measure afingerprint is the ability to penetrate through thicker layers of glassand transparent plastic as well as image through metal and opaque glassor plastic layers. Other advantages of using ultrasonic technologyinclude higher resolution (in the range of 500-2000 PPI), the potentialfor scanning the internal structure of a finger (e.g., capillaries)which would make it extremely difficult to spoof, being able todetermine heart rate, and an improved ability to cope with sweaty anddirty fingers.

The above-described functions of the fingerprint sensor 140 may beimplemented by a control unit. That is, the control unit of thefingerprint sensor 140 can recognize a fingerprint of a user byprocessing ultrasonic waves transmitted and received from the sensorelectrode 144.

The electroluminescence display panel 110 may be configured to includeat least the substrate 112, the transistor TFT, the electroluminescenceelement 122, and the encapsulation unit 128, 130, 132 (e.g., a firstencapsulation unit 128, a second encapsulation unit 130, and a thirdencapsulation unit 132).

The substrate 112 may be made of rigid glass. The substrate 112 supportsvarious elements of the electroluminescence display panel 110. On thesubstrate 112, a transistor TFT is disposed. The transistor TFT asillustrated in FIG. 5 as an example may correspond to the structure ofthe switching transistor and the driving transistor of the pixel PXL,which is exemplarily described.

The transistor TFT may be configured to include a semiconductor layer A,a first insulating layer 114 configured to insulate the semiconductorlayer A from a gate electrode G, the gate electrode G configured tooverlap with the semiconductor layer A on the first insulating layer114, a second insulating layer 116 configured to insulate the gateelectrode G, the source electrode S and the drain electrode D, and asource electrode S and a drain electrode D configured to be electricallyconnected to the semiconductor layer A through the contact hole on thesecond insulating layer 116. The above-described transistor TFTstructure may be referred to as a transistor of a co-planar structure.

The first insulating layer 114 and the second insulating layer 116 maybe formed of an inorganic insulating material such as silicon nitride(SiNx), silicon oxide (SiOx), or silicon oxynitride (SiON).

However, the transistor according to the embodiments of the presentdisclosure is not limited thereto and may be implemented by transistorshaving various structures. For example, the transistor may be configuredas an inverted staggered structure.

The third insulating layer 118 may be formed on the transistor TFT toflatten the upper portion of the transistor TFT. The anode 120 and thetransistor TFT may be electrically connected to each other through thecontact hole CNT formed in the third insulating layer 118. The thirdinsulating layer 118 may be made of an organic material having aplanarizing property for planarization. For example, photo-acrylic orpolyimide may be used as the organic material.

An electroluminescence element 122 is disposed on the anode 120 and acathode 126 is disposed on the electroluminescence element 122.

The anode 120 may be connected to a transistor TFT to receive current.The anode 120 is electrically connected to the drain electrode D of thetransistor TFT through a contact hole passing through the thirdinsulating layer 118. The electroluminescence element 122 is disposed onthe anode 120 surrounded by a bank 124. A spacer may be disposed on someportions of the bank 124. The spacer may be formed in such a way thatthe height of a portion of the bank 124 is made higher through ahalftone exposure technique.

The electroluminescence element 122 may be disposed in the lightemitting region of the pixel. The electroluminescence element 122 mayhave a single-layered structure or a multi-layered structure. Forexample, the electroluminescence element 122 may further include ahole-transporting layer, an electron-transporting layer, and the like.The electroluminescence element 122 may include a light emittingmaterial corresponding to a particular color of a pixel to display theparticular color of each pixel.

In the case of an organic light emitting diode, the electroluminescenceelement 122 may be formed of an organic material.

In the case of an inorganic light emitting diode, theelectroluminescence element 122 may be made of an inorganic material.For example, when an inorganic light-emitting diode is formed using aquantum-dot material, it may be referred to as a quantum-dot lightemitting diode.

The electroluminescence elements 122 may be formed individuallyaccording to the intrinsic color of each pixel. However, the presentdisclosure is not limited thereto, and when all the pixels have a whitecolor, the electroluminescence layer may be formed as a common layer.The common layer may refer to a layer formed in all areas of the displayarea AA.

The hole-transporting layer and/or the electron-transporting layer mayprovide a function of facilitating the movement of holes and electronsin the electroluminescence layer. The hole-transporting layer and/or theelectron-transporting layer may be formed as a common layer. However,the present disclosure is not limited thereto, and the hole-transportinglayer and/or the electron-transporting layer may be selectively appliedto improve the characteristics of each pixel. In such case, thehole-transporting layer and/or the electron-transporting layer may beformed in a particular region of the display area AA. In addition, it ispossible to have different thicknesses of the electroluminescence layerdepending on the pixel.

The cathode 126 is formed to face the anode 120 with theelectroluminescence element 122 between the cathode 125 and the anode120. When the cathode 126 is formed in such a manner as to cover thedisplay area AA, the cathode 126 may be referred to as a commonelectrode.

The encapsulation unit 128, 130, 132 may be configured to suppressmoisture or oxygen from penetrating into the electroluminescence element122, which may be vulnerable to moisture or oxygen. The encapsulationunit 128, 130, 132 may be formed to protect the electroluminescenceelement 122 in particular, since the electroluminescence element 122 maybe particularly vulnerable to moisture and oxygen when theelectroluminescence element 122 includes an organic material. For thispurpose, the encapsulation unit 128, 130, 132 may include at least afirst inorganic encapsulation layer 128, an organic encapsulation layer130 on the first inorganic encapsulation layer 128 and a secondinorganic encapsulation layer 132 on the organic encapsulation layer130. That is, the encapsulation unit 128, 130, 132 may be configured toinclude at least two inorganic encapsulation layers 128 and 132 and atleast one organic encapsulation layer 130.

The encapsulation unit 128, 130, 132 of the electroluminescence displaypanel 110 according to an embodiment of the present disclosure may bedescribed as a structure in which the organic encapsulation layer 130 issealed between the first inorganic encapsulation layer 128 and thesecond inorganic encapsulation layer 132.

The first inorganic encapsulation layer 128 may be disposed on thecathode 126. The first inorganic encapsulation layer 128 may beconfigured to seal a plurality of pixels arranged in the display areaAA. The first inorganic encapsulation layer 128 may extend to at least aportion of the non-display area NA. The first inorganic encapsulationlayer 128 may be formed of an inorganic insulating material capable oflow temperature deposition technique such as silicon nitride (SiNx),silicon oxide (SiOx), silicon oxynitride (SiON), or aluminum oxide(Al2O3). Accordingly, since the first inorganic encapsulation layer 128is deposited in a low-temperature atmosphere, it is possible to minimizethe electroluminescence element 122, which is vulnerable to ahigh-temperature atmosphere, from being damaged during the depositionprocess of the first inorganic encapsulation layer 128. For example,when the first inorganic encapsulation layer 128 is formed of siliconnitride, the thickness of the first inorganic encapsulation layer 128can be set to 0.1 μm to 1.5 μm. However, the present disclosure is notlimited thereto. In other words, the Young's modulus of silicon nitride,which is an exemplary inorganic material, can be approximately 100 GPato 300 GPa. The Young's modulus of the silicon oxide, which is anexemplary inorganic material, can be approximately 70 GPa to 100 GPa.However, the present disclosure is not limited thereto. Since theencapsulation layer made of a silicone substance may have an excellentYoung's modulus value, it has characteristics suitable for ultrasonictransmission and reception.

The organic encapsulation layer 130 serves as a buffer for relieving thestress between the respective layers of the electroluminescence displaypanel 110, enhances the planarization performance, and compensates forforeign matter. Therefore, the flatness and quality of the secondinorganic encapsulation layer 141 can be improved. The organicencapsulation layer 130 may be formed of an organic insulating materialsuch as acrylic resin, epoxy resin, polyimide, polyethylene, or siliconoxycarbon (SiOC). The organic encapsulation layer 130 may be formed by achemical vapor deposition method, an inkjet printing method, or asqueegee method. Further, the organic encapsulation layer 130 can beformed by easily adjusting the thickness. Therefore, the thickness ofthe encapsulation unit 128, 130, 132 can be easily controlled byadjusting the thickness of the organic encapsulation layer 130. Inaddition, for convenience of explanation, the thickness of the organicencapsulation layer 130 of the electroluminescence display panel 110according to an embodiment of the present disclosure will be describedwith reference to the center region of the electroluminescence element122.

The second inorganic encapsulation layer 132 may be configured to sealthe organic encapsulation layer 130. The second inorganic encapsulationlayer 132, may cover the organic encapsulation layer 130, may beconfigured to contact the first inorganic encapsulation layer 128 toprevent the organic encapsulation layer 130 from being exposed to theoutside. In particular, when the side surface of the organicencapsulation layer 130 is exposed to the outside, the organicencapsulation layer 130 may become a moisture and oxygen permeation pathfor moisture and oxygen, thus, the organic encapsulation layer 130 maybe sealed by the first inorganic encapsulation layer 128 and the secondinorganic encapsulation layer 132. Accordingly, the first inorganicencapsulation layer 128 and the second inorganic encapsulation layer 132may be configured to extend further outward than the edge of the organicencapsulation layer 130. Therefore, the organic encapsulation layer 130can be sealed, and the first inorganic encapsulation layer 128 and thesecond inorganic encapsulation layer 132 can be configured to contacteach other in the non-display area NA. Particularly, when the firstinorganic encapsulation layer 128 and the second inorganic encapsulationlayer 132 are configured to seal each other to seal the organicencapsulation layer 130, moisture and oxygen permeable to the organicencapsulation layer 130 can be effectively protected. The secondinorganic encapsulation layer 132 may be formed of an inorganicinsulating material capable of low temperature deposition technique suchas silicon nitride (SiNx), silicon oxide (SiOx), silicon oxynitride(SiON), or aluminum oxide (Al2O3). For example, when the secondinorganic encapsulation layer 132 is formed of silicon nitride, thethickness of the second inorganic encapsulation layer 132 can be set to0.1 μm to 1.5 μm. However, the present disclosure is not limitedthereto.

The fingerprint sensor 140 of the display device 100 according to anembodiment of the present disclosure may be arranged under the rear sideof the electroluminescence display panel 110. In more detail, thefingerprint sensor 140 according to an embodiment of the presentdisclosure may be attached to the rear side of the substrate 112 of theelectroluminescence display panel 110.

A display device 100 according to an embodiment of the presentdisclosure includes a substrate 112, a transistor (TFT) on the substrate112, an electroluminescence element 122 on the transistor TFT, anencapsulation unit 128, 130, 132 on the electroluminescence element 122and an ultrasonic fingerprint sensor 140 under the rear side of thesubstrate 112, wherein the substrate 112, the transistor TFT, theelectroluminescence element 122, and the encapsulation unit 128, 130,132 corresponding to the fingerprint sensor 140 may serve as a channelfor ultrasonic transmission and reception of the fingerprint sensor 140.

The first adhesive member 150 may be configured to attach thefingerprint sensor 140 and the electroluminescence display panel 110.For example, when the fingerprint sensor 140 and the electroluminescencedisplay panel 110 are disposed close to each other without the firstadhesive member 150, a gap or a space may be formed between thefingerprint sensor 140 and the electroluminescence display panel 110.Such a space can significantly affect the ultrasonic signal attenuationin the high frequency band for fingerprint recognition. Therefore, it ispreferable that any gap should not be formed.

An area, corresponding to a substrate 112, a transistor TFT, anelectroluminescence element 122 and an encapsulation unit 128, 130, 132,serving as a transmission and reception channel of the fingerprintsensor 140 of the display device 100 according to an embodiment of thepresent disclosure may be configured as a gas-free, a gap-free, and aspace-less so as to eliminate the cause of obstructing the transmissionand reception of ultrasonic waves.

The display device 100 according to an embodiment of the presentdisclosure may be configured such that there is no space or gap betweenthe fingerprint sensor 140 and the electroluminescence display panel 110by the first adhesive member 150. Therefore, it is possible to minimizedeterioration of the transmission and reception sensitivity between thefingerprint sensor 140 and the electroluminescence display panel 110.The first adhesive member 150 may be configured to adhere thefingerprint sensor 140 to the substrate 112 and may be configured tohave a particular thickness and a particular Young's modulus valuesuitable for ultrasonic transmission and reception.

As the density or the Young's modulus of the first adhesive member 150increases, the ultrasonic transmission and reception sensitivity can beimproved. In addition, as the thickness of the first adhesive member 150becomes decreases, the ultrasonic transmission and reception sensitivitycan be improved. The first adhesive member 150 may be applied to aregion where the fingerprint sensor 140 and the substrate 112 areoverlapped with each other. That is, the first adhesive member 150 maybe applied to correspond to the area of the fingerprint sensor 140.

The first adhesive member 150 according to an embodiment of the presentdisclosure may be made of a curable adhesive material. That is, thefirst adhesive member 150 may be made of a resin that is defoamed andcured by a curable adhesive material. As the curable adhesive material,for example, materials such as acrylic, epoxy, and the like can be used.However, the present disclosure is not limited thereto. In other words,the Young's modulus of the epoxy, which is an exemplary adhesive member,can be approximately 2 GPa to 4 GPa. However, the present disclosure isnot limited thereto. In the case of epoxy, since the Young's modulus isa relatively high material, the ultrasonic signal level may not bepractically attenuated in ultrasonic transmission.

The thickness of the first adhesive member 150 of the display device 100according to an embodiment of the present disclosure may be 5 μm to 15μm. According to the thickness described above, it is possible to reducethe occurrence of bubbles or a foam while minimizing deterioration ofthe ultrasonic transmission/reception characteristics, and to provide asufficient adhesive force. However, the present disclosure is notlimited thereto. In other words, the adhesive member 150 may be a resinhaving a property of being defoamed, and the air bubbles may be removedin a cured state, so that the ultrasonic transmission/reception qualitymay not be reduced.

The color of the first adhesive member 150 according to an embodiment ofthe present disclosure may be transparent or opaque. In other words, inthe case of ultrasonic waves, fingerprints can be recognizedirrespective of the light transmittance of the first adhesive member150.

The first adhesive member 150 according to an embodiment of the presentdisclosure may be configured not to include a substance having a lowdensity (e.g., low Young's modulus) such as bubbles or gas. For example,if the first adhesive member is a foam tape, since the foam tapecontains a plurality of bubbles, the ultrasonic transmission andreception sensitivity can be rapidly lowered. Therefore, difficulties infingerprint recognition may arise.

In other words, the first adhesive member 150 may be a resin thatremoves air bubbles, which may interfere with the transmission andreception of ultrasonic waves, or does not contain air bubbles.

According to the first adhesive member 150 according to the embodimentof the present disclosure as described above, the gap between thefingerprint sensor 140 and the electroluminescence display panel 110 canbe removed and the fingerprint sensor 140 and the electroluminescencedisplay panel 110 can be adhered, thereby facilitating the ultrasonictransmission and reception.

On the other hand, if one or both of the rear side of the substrate 112and the surface of the fingerprint sensor 140 that are in contact witheach other are implemented or treated with a material having sufficientself-adhesive force, and then the first adhesive member 150 may not berequired. In this case, the ultrasonic transmission and reception may befurther improved.

Hereinafter, the electroluminescence display panel 110 will be describedin terms of the ultrasonic transmission and reception channel of thefingerprint sensor 140.

The electroluminescence display panel 110 according to an embodiment ofthe present disclosure is designed in consideration of ultrasonictransmission and reception.

The electroluminescence display panel 110 according to an embodiment ofthe present disclosure may include a flexible substrate 112, having athickness of 3 μm to 30 μm, configured to transmit ultrasonic waves in afingerprint recognition area FDA, a transistor TFT, on the flexiblesubstrate 112, configured to transmit ultrasonic waves in thefingerprint recognition area FDA, an electroluminescence element 122, onthe transistor TFT, configured to transmit ultrasonic waves in thefingerprint recognition area FDA, a first inorganic encapsulation layer128, on the electroluminescence element 122, configured to transmitultrasonic waves in the fingerprint recognition area FDA, an organicencapsulation layer 130, on the first inorganic encapsulation layer 128,having a thickness of 3 μm to 10 μm, configured to transmit ultrasonicwaves in a fingerprint recognition area FDA, and a second inorganicencapsulation layer 132, on the organic encapsulation layer 130,configured to transmit ultrasonic waves in the fingerprint recognitionarea FDA.

The transmission and reception channel of the fingerprint sensor 140 ofthe display device 100 according to an embodiment of the presentdisclosure may be configured such that ultrasonic waves output from thefingerprint sensor 140 are reflected by a fingerprint of a user'sfinger.

For example, the substrate 112 may be formed of glass. As the glasssubstrate has high density or high Young's modulus value, it can beadvantageous for ultrasonic transmission and reception. Further, sincethe rigidity is excellent even when the fingerprint sensor 140 isattached to the substrate 112, the deformation of the substrate 112 canbe minimized.

For example, a portion of the insulating layers of theelectroluminescence display panel 110 may be made of an inorganicmaterial. The inorganic material is relatively high in Young's moduluscompared to the organic material and can be relatively thin in thicknesscompared to the organic material. Thus, the inorganic material may haveless influence to the ultrasonic transmission and reception than theorganic material.

For example, a part of the insulating layer and a part of theencapsulation unit of the electroluminescence display panel 110 may bemade of an organic material. The organic material has a relatively lowYoung's modulus as compared to an inorganic material. In addition, theorganic material may have a planarizing property and may have arelatively thicker thickness than the inorganic material. In addition,the organic material can easily control its thickness. Thus, the organicmaterial may have a greater effect on signal sensitivity to ultrasonictransmission and reception than the inorganic material. Accordingly, itis possible to control the sensitivity of the ultrasonic signal of thefingerprint sensor 140 by adjusting the thickness of the insulatinglayers made of the organic material.

The thickness of the organic encapsulation layer 130 of theencapsulation unit 128, 130, 132 of the electroluminescence displaypanel 110 according to an embodiment of the present disclosure may be 3μm to 10 μm. According to the thickness described above, at the sametime, the organic encapsulation layer 130, may compensate the foreignmatter of the first inorganic encapsulation layer 128, may planarize thesecond inorganic encapsulation layer 132, and may perform as atransmission and reception channel of the ultrasonic wave forfingerprint recognition.

A display device 100 (i.e., an apparatus) according to an embodiment ofthe present disclosure may include an electroluminescence display panel110 including a substrate 112, a transistor TFT positioned on thesubstrate 112, an electroluminescence element 122 positioned on thetransistor TFT, an encapsulation unit 128, 130, 132 positioned on thethe electroluminescence element 122, and a fingerprint sensor 140,positioned under the rear side of the electroluminescence display panel110, configured to output a signal having a frequency from 10 MHz to 15MHz, wherein the encapsulation unit 128, 130, 132 may include a firstinorganic encapsulation layer 128 adjacent to the electroluminescenceelement 122, an organic encapsulation layer 130 on the first inorganicencapsulation layer 128, and the second inorganic encapsulation layer132 on the organic encapsulation layer 130, and wherein the thickness ofthe organic encapsulation layer 130 may be between 3 μm to 10 μm. Thus,the Tx electrodes 141 of the fingerprint sensor 140 may generate asuitable frequency of an ultrasonic wave to pass through the allelements such as the transistor TFT, the electroluminescence element122, and the encapsulation unit 128, 130, 132 of the electroluminescencedisplay panel 110 and the Rx electrodes 143 may receive the reflectedultrasonic wave by the sensor electrode 144.

In addition, the encapsulation unit 128, 130, 132 may be configured toinclude at least two inorganic encapsulation layers having a Young'smodulus from 70 GPa to 300 GPa.

The fingerprint sensor 140 of the display apparatus 100 according to anembodiment of the present disclosure can detect a user's fingerprintthat is in contact with the electroluminescence display panel 110 usinga frequency of 10 MHz or more, for example, a frequency of 10 MHz to 15MHz, and recognize the shape of the fingerprint by recognizing thedifference in reflection characteristics of the space (e.g., air) in thevalley between the skin portions of the fingerprint. In one embodiment,the fingerprint sensor 140 may transmit a signal that has a frequencythat can travel through air (e.g., less than 10 MHz) while stillproviding high resolution of a user's fingerprint.

In one embodiment, the fingerprint sensor 140 may operate in afingerprint sensing mode and a proximity sensor mode. In the fingerprintsensing mode, the fingerprint sensor 140 outputs a signal at a frequency(e.g., 10 Mhz to 15 Mhz) for recognizing the shape of the fingerprint.In the proximity sensor mode, the fingerprint sensor 140 outputs asignal at a frequency that is less than the frequency of the fingerprintsensor mode. In the proximity sensor mode, the fingerprint sensor 140may be used to determine whether the display device is next to aperson's face.

In addition, a conventional electroluminescence display panel having aglass substrate generally implemented a frit-seal structure in which aglass portion is melted in a non-display area to form a sealed portionby sealing a non-display region. The conventional frit-seal structurehas a simple process and excellent moisture permeability. However, sincethe frit-seal structure is filled with nitrogen gas above the cathode,there is a problem that the ultrasonic wave for fingerprint recognitionis absorbed. Therefore, the embodiments of the present disclosure withthe fingerprint sensor 140 may implement a sealing structure such as aface-seal structure, which is suitable for the fingerprint detection.However, the conventional frit-seal structure is not suitable for thefingerprint detection.

The encapsulation unit 128, 130, 132 of the electroluminescence displaypanel 110 according to an embodiment of the present disclosure isconfigured not to include any gap or any gas layer along the ultrasonictransmission and reception channel region. That is, between thefingerprint sensor 140 and the electroluminescence display panel 110,there should not be any objects or any space that can attenuate theultrasonic signal.

According to the above-described configuration, the display device 100according to an embodiment of the present disclosure may provide afingerprint sensor 140, an electroluminescence display panel 110 capableof providing a transmission and reception channel or path of thefingerprint sensor 140 while displaying an image by emitting a pluralityof pixels PXL, and a first adhesive member 150 for attaching theelectroluminescence display panel 110 and the fingerprint sensor 140,thereby recognizing the fingerprint in a fingerprint recognition areawhere an image is displayed.

FIG. 6 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to anotherembodiment of the present disclosure.

Redundant features of the display device 200 according to anotherembodiment of the present disclosure and the display device 100according to an embodiment of the present disclosure may be omittedmerely for the sake of convenience of explanation.

Hereinafter, specific elements of the electroluminescence display panel110 may be described with reference to FIG. 5, if necessary.

The features of the electroluminescence display panel 110, thefingerprint sensor 140, and the first adhesive member 150 of the displaydevice 200 according to another embodiment of the present disclosure maybe implemented substantially the same as the features of theelectroluminescence display panel 110, the fingerprint sensor 140, andthe first adhesive member 150 of the display device 100 according to anembodiment of the present disclosure. Thus, the redundant descriptionswith respect to the electroluminescence display panel 110, thefingerprint sensor 140, and the first adhesive member 150 may be omittedmerely for convenience of explanation.

The electroluminescence display panel 110 of the display device 200according to another embodiment of the present disclosure may beconfigured to include a flexible substrate 112, having a thickness of 3μm to 30 μm, configured to transmit ultrasonic waves in a fingerprintrecognition area FDA, a transistor TFT, on the flexible substrate 112,configured to transmit ultrasonic waves in the fingerprint recognitionarea FDA, an electroluminescence element 122, on the transistor TFT,configured to transmit ultrasonic waves in the fingerprint recognitionarea FDA, a first inorganic encapsulation layer 128, on theelectroluminescence element 122, configured to transmit ultrasonic wavesin the fingerprint recognition area FDA, an organic encapsulation layer130, on the first inorganic encapsulation layer 128, having a thicknessof 3 μm to 10 μm, configured to transmit ultrasonic waves in afingerprint recognition area FDA, and a second inorganic encapsulationlayer 132, on the organic encapsulation layer 130, configured totransmit ultrasonic waves in the fingerprint recognition area FDA. Thesubstrate of the electroluminescence display panel 110 of the displaydevice 200 according to another embodiment of the present disclosure maybe formed of a material having a flexibility characteristic. Forexample, the material of the substrate having flexibility properties maybe a polymer resin such as polyethersulphone, polyacrylate,polyetherimide, polyethyelenen-napthalate, polyethylene-terephthalate(PET), polyphenylene-sulfide, polyallylate, polyimide (PI),polycarbonate, photoacrylic, cellulose-acetate-propionate (CAP) or thelike. The flexible substrate 112 may be configured to absorb visiblelight.

If the substrate of the electroluminescence display panel 110 is aflexible substrate other than glass, for example, in the case of asubstrate formed of a polyimide material, the density and/or the Young'smodulus may be relatively lower than that of glass.

The substrate of the electroluminescence display panel 110 of thedisplay device 200 according to another embodiment of the presentdisclosure may be made of a flexible material. In other words, theexemplary flexible substrate may be composed of polyimide, and in thiscase, the Young's modulus of the flexible substrate may be approximately1.5 GPa to 3 GPa. For example, when the substrate is made of polyimide,the thickness may be 3 μm to 30 μm. However, the present disclosure isnot limited thereto. Since the substrate made of polyimide has excellentYoung's modulus, it may have suitable characteristics for ultrasonictransmission and reception.

If the thickness of the flexible substrate is 30 μm or more, theflexibility of the electroluminescence display panel 110 can be reduced.If the thickness of the substrate is less than 3 μm, it may be difficultfor the substrate to sufficiently support the elements disposed on theelectroluminescence display panel 110.

The substrate of the electroluminescence display panel 110 is formed asa flexible material and directly bonded to the substrate with the firstadhesive member 150. As a result, it has been observed that the displayarea of the display device where the fingerprint sensor 140 is attachedis deformed unevenly due to the stress exerted during the curing of thefirst adhesive member 150, so that the image quality was reduced.

Thus, the display device 200 according to another embodiment of thepresent disclosure further includes a support substrate 160 and a secondadhesive member 152 disposed between the electroluminescence displaypanel 110 and the first adhesive member 150. In such case, the substrate112 of the electroluminescence display panel 110 may be configured tohave a flexible characteristic.

The support substrate 160 is disposed between the fingerprint sensor 140and the electroluminescence display panel 110 including the flexiblesubstrate so that the flatness of the electroluminescence display panel110 can be improved from being deformed by the stress of the firstadhesive member 150.

That is, the support substrate 160 may be disposed between theelectroluminescence display panel 110 and the fingerprint sensor 140 tosupport the fingerprint sensor 140 and the electroluminescence displaypanel 110. The first adhesive member 150 may be disposed between thesupport substrate 160 and the electroluminescence display panel 110 tobond the supporting substrate 160 to the electroluminescence displaypanel 110.

In addition, it is not desirable that there is an empty space in theultrasonic transmission and reception path or channel of the fingerprintsensor 140, and therefore, an adhesive member capable of filling anyempty space is required. However, the first adhesive member may causestress due to its adhesiveness. Therefore, the stress caused by thefirst adhesive member 150 needs to be reduced.

The support substrate 160 of the display device 200 according to anotherembodiment of the present disclosure may be adhered to theelectroluminescence display panel 110 by the second adhesive member 152.Further, the fingerprint sensor 140 may be adhered to the supportsubstrate 160. The support substrate 160 may be configured to support adisplay area AA of the electroluminescence display panel 110 and anon-display area NA surrounding the periphery of the display area AA.

The support substrate 160 may be made of, for example,polyethylene-terephthalate (PET). In other words, the Young's modulus ofthe exemplary support substrate 160 may be approximately 2.5 GPa to 3.5GPa. However, the present disclosure is not limited thereto. Forexample, when the support substrate 160 is made ofpolyethylene-terephthalate, the thickness may be 50 μm to 150 μm.However, the present disclosure is not limited thereto. The supportsubstrate made of polyethylene-terephthalate has characteristicssuitable for ultrasonic transmission and reception because of itsexcellent Young's modulus value.

Further, the control unit of the fingerprint sensor 140 may beconfigured to transmit ultrasonic waves having a proper frequency topass through the electroluminescence display panel 110 and the supportsubstrate 160 under the back side of the electroluminescence displaypanel 110, for example, ultrasonic waves having a frequency of 10 MHz to15 MHz can be generated and transmitted and then received through the Txelectrodes 141 and the Rx electrodes 143.

According to another embodiment of the present disclosure, the supportsubstrate 160, in the region where the fingerprint sensor 140 isattached, of the display device 200 can suppress the deformation of theflatness of the electroluminescence display panel 110 due to the stressexerted by the curing of the adhesive member 150. The support substrate160 may be placed under the rear surface of the flexible substrate 112,which is configured to transmit ultrasonic waves in the fingerprintrecognition area FDA. A fingerprint sensor 140 configured to generateultrasonic waves in the fingerprint recognition area FDA may be placedunder the rear surface of the supporting substrate 160.

The support substrate 160 may have a transparent or opaquecharacteristic. The support substrate 160 may be configured to absorbvisible light.

When the support substrate 160 is transparent, it is convenient toperform a vision inspection to inspect various defects such as bubblesgenerated when the support substrate 160 is attached to theelectroluminescence display panel 110 during the fabrication process,signal wiring defects of the electroluminescence display panel 110, orthe like defects. In addition, if any bubbles are present, ultrasonictransmission and reception degradation may occur.

Even if the support substrate 160 is opaque, the visible lighttransmittance of the support substrate 160 does not have a particularinfluence on the ultrasonic transmission and reception. For example, thevisible light absorption rate of the supporting substrate 160 may be 80%or more.

The second adhesive member 152 may be, for example, a pressure-sensitiveadhesive (PAS). In other words, the Young's modulus of the exemplarypressure-sensitive adhesive member may be approximately 0.02 MPa to 0.4MPa. However, the present disclosure is not limited thereto.

When the second adhesive member 152 is a pressure-sensitive adhesivehaving a Young's modulus value relatively lower than the other elements,the performance of the ultrasonic transmission and reception channel maybe deteriorated as the thickness of the second adhesive member 152increases.

The thickness of the second adhesive member 152 of the display device200 according to another embodiment of the present disclosure may be 5μm to 15 μm. According to the thickness described above, it is possibleto provide a sufficient adhesive force while reducing the occurrence ofbubbles while minimizing deterioration of the ultrasonic transmissionand reception characteristics. However, the present disclosure is notlimited thereto.

According to the above-described configuration, the display device 200according to another embodiment of the present disclosure can reduce thedeformation of the display device 200 by the support substrate 160 evenif the fingerprint sensor 140 is attached by the first adhesive member150. Therefore, the appearance and image quality of the display device200 can be improved. In addition, the thickness of the second adhesivemember 152 can be adjusted to remedy deformation of the substrate of theelectroluminescence display panel 110 while minimizing deterioration insignal sensitivity with respect to the ultrasonic transmission andreception channel.

FIG. 7 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure.

Redundant features of the display device 300 according to the otherembodiment of the present disclosure and the display device 200according to another embodiment of the present disclosure may be omittedmerely for the sake of convenience of explanation.

The features of the electroluminescence display panel 110, thefingerprint sensor 140, the support substrate 160, and the secondadhesive member 152 of the display device 300 according to the otherembodiment of the present disclosure may be implemented substantiallythe same as the features of the electroluminescence display panel 110,the fingerprint sensor 140, the support substrate 160, and the secondadhesive member 152 of the display device 200 according to anotherembodiment of the present disclosure. Thus, the redundant descriptionswith respect to the electroluminescence display panel 110, thefingerprint sensor 140, the support substrate 160, and the secondadhesive member 152 may be omitted merely for convenience ofexplanation.

The first adhesive member 150-1 of the display device 300 according tothe other embodiment of the present disclosure may be configured tocorrespond to the support substrate 160.

For example, the first adhesive member 150-1 may be configured to coverthe rear surface of the support substrate 160, or may have a specificarea corresponding to the support substrate 160.

For example, the first adhesive member 150-1 may be configured tooverlap at least the display area AA of the electroluminescence displaypanel 110. That is, the first adhesive member 150-1 may be configured tocover the display area AA of the electroluminescence display panel 110.

For example, the first adhesive member 150-1 may be configured tooverlap at least the display area AA and the non-display area NA of theelectroluminescence display panel 110.

For example, the second adhesive member 152 may be disposed on the frontsurface of the supporting substrate 160, and the first adhesive member150-1 may be disposed under the rear surface of the supporting substrate160.

For example, the first adhesive member 150-1 and the second adhesivemember 152 may be made of the same material.

The adhesive member 150-1 may be configured to have a predeterminedthickness in consideration of transmission characteristics of ultrasonicfrequency for fingerprint recognition.

The first adhesive member 150-1 may be composed of a pressure-sensitiveadhesive. In other words, the Young's modulus of the exemplarypressure-sensitive adhesive member may be approximately 0.02 MPa to 0.4MPa. At this time, the thickness of the first adhesive member 150-1 maybe 5 μm to 15 μm. However, the present disclosure is not limitedthereto.

According to the above-described configuration, the first adhesivemember 150-1 can provide sufficient adhesion force to support thefingerprint sensor 140 and the supporting substrate 160 while minimizingdegradation of ultrasonic transmission and reception characteristics.Unlike the first adhesive member 150 according to an embodiment of thepresent disclosure, the first adhesive member 150-1 according to theother embodiment of the present disclosure may be formed as a film-typeadhesive on the supporting substrate 160 and then adhered to thefingerprint sensor 140. In this case, since the first adhesive member150-1 may not require additional curing process, the stress may bereduced as compared to the first adhesive member 150 according to anembodiment of the present disclosure. Therefore, deformation of theflatness of the electroluminescence display panel 110 can be relativelyreduced by the first adhesive member 150-1 than that of the firstadhesive member 150.

In addition, since the first adhesive member 150-1 can be provided inother areas other than the fingerprint sensor 140, elements other thanthe fingerprint sensor 140 can be adhered. In addition, a plurality offingerprint sensors 140 may be attached at various positions.

FIG. 8 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure.

Redundant features of the display device 400 according to the otherembodiment of the present disclosure and the display device 200according to another embodiment of the present disclosure may be omittedmerely for the sake of convenience of explanation.

The features of the electroluminescence display panel 110, thefingerprint sensor 140, the support substrate 160, and the secondadhesive member 152 of the display device 400 according to the otherembodiment of the present disclosure may be implemented substantiallythe same as the features of the electroluminescence display panel 110,the fingerprint sensor 140, the support substrate 160, and the secondadhesive member 152 of the display device 200 according to anotherembodiment of the present disclosure. Thus, the redundant descriptionswith respect to the electroluminescence display panel 110, thefingerprint sensor 140, the support substrate 160, and the secondadhesive member 152 may be omitted merely for convenience ofexplanation.

The fingerprint sensor 140 is bonded to the electroluminescence displaypanel 110 with the first adhesive member 150. When the fingerprintsensor 140 is attached to the electroluminescence display panel 110 andexposed to external light for a certain time or more, the degree ofexternal light exposure of the TFT corresponding to the fingerprintrecognition area FDA of the electroluminescence display panel 110 may bedifferent from the area other than the fingerprint recognition area FDA.Further, it has been observed that due to the difference, defects mayoccur, for example, shadow-mura, in which the transistor TFTcharacteristics of the pixel PXL may be changed in the region where thefingerprint sensor 140 is attached.

Thus, the display device 400 according to the other embodiment of thepresent disclosure may be configured to include the light-shield member162 disposed between the supporting substrate 160 and the fingerprintsensor 140.

The display device 400 according to the other embodiment of the presentdisclosure may include an electroluminescence display panel 110including a fingerprint detection area (fingerprint recognition area), adisplay area AA configured to display an image and a non-display area NAaround the display area AA, a support substrate 160 configured tosupport the electroluminescence display panel 110, a fingerprint sensor140 under the rear surface of the support substrate 160, and alight-shield member 162, under the support substrate 160, configured tolight-shield the fingerprint sensor 140.

A display device 400 according to the other embodiment of the presentdisclosure may include an electroluminescence display panel 110including a plurality of pixels PXL, a support substrate 160 adhered toa rear side of the electroluminescence display panel 110, a light-shieldmember 162 under at least a portion of a rear side of the supportsubstrate 160, and a fingerprint sensor 140 attached to the rear side ofthe light-shield member 162 by a first adhesive member 150.

A display device 400 according to the other embodiment of the presentdisclosure may include an electroluminescence display panel 110including a plurality of pixels PXL on a flexible substrate and anencapsulation unit covering the plurality of pixels PXL, a transparentsupport substrate 160 under a rear surface of the electroluminescencedisplay panel 110, a light-shield member 162 at a certain area of a rearsurface of the transparent support substrate 160, a cushion member 168,including an opening corresponding to the certain area, under the rearsurface of the transparent support substrate 160, and a ultrasonicfingerprint sensor 140 attached to the light-shield member 162 at theopening.

The light-shield member 162 may suppress the occurrence of shadow-muradue to the attachment of the fingerprint sensor 140. The light-shieldmember 162 can minimize the deterioration of the signal sensitivity ofthe ultrasonic transmission and reception channel of the fingerprintsensor 140. Thus, the control unit of the fingerprint sensor 140 maygenerate ultrasonic waves of a suitable frequency to pass through thelight-shield member 162 disposed under the rear surface of theelectroluminescence display panel 110. For example, 10 MHz to 15 MHzsignal may be generated, and then the Tx electrodes 141 and Rxelectrodes 143 may transmit and receive the ultrasonic waves.

The light-shield member 162 may be configured to shield at least thearea where the fingerprint sensor 140 and the electroluminescencedisplay panel 110 overlap. However, the present disclosure is notlimited thereto, and the light-shield member 162 may be configured toshield all of the display area AA. Further, the light-shield member 162may be configured to shield the display area AA and the non-display areaNA.

The light-shield member 162 may be made of a material having a materialhaving at least 80% of a visible light absorption rate. However, thepresent disclosure is not limited thereto. As an example, if the displaydevice including the electroluminescence display panel 110 is used in anautomobile interior or in an environment with a large influence ofvisible light, such as a kiosk in a public place, and then it may besuitably applied by adjusting the area, thickness, absorption rate, andthe like of the light-shield member 162.

For example, the light-shield member 162 may include a visible lightabsorbing dye or a polyethylene-terephthalate having a black color. Thelight-shield member 162 may be configured to include at least one ofgraphite, carbon, and graphene.

The light-shield member 162 may be coated directly to the rear side ofthe support substrate 160 or may be bonded together by a separatebonding member. When the light-shield member 162 is made ofpolyethylene-terephthalate, the thickness of the light-shield member 162may be made thinner than the thickness of the support substrate 160.That is, since the light-shield member 162 shields the fingerprintsensor 140 from the electroluminescence display panel 110, the thicknessof the support substrate 160 for providing the flatness of theelectroluminescence display panel 110 can be relatively thinner.However, the present disclosure is not limited thereto. For example, thethickness of the light-shield member 162 including polyethyleneterephthalate may be 10 μm to 25 μm.

For example, the light-shield member 162 may be made of a lightabsorbing ink. The light-shield member 162 may be coated directly underthe rear surface of the support substrate 160. When the light-shieldmember 162 is a light absorbing ink, the thickness of the light-shieldmember 162 may be made thinner than the thickness of the supportsubstrate 160. For example, the thickness of the light-shield member 162including the light absorbing ink may be 8 μm to 20 μm. According to theabove-described configuration, even if the fingerprint sensor 140 isattached by the light-shield member 162, the occurrence of shadow-murain the electroluminescence display panel 110 can be suppressed and thedeterioration of signal sensitivity of the ultrasonic transmission andreception channel can be minimized. In addition, the flatness of theelectroluminescence display panel 110 can be improved by thelight-shield member 162. In addition, the thickness of the light-shieldmember 162 may be 8 μm to 25 μm.

The thickness of the light-shield member 162 may be thinner than thethickness of the support substrate 160 and the thickness of thelight-shield member 162 may be made thinner than the thickness of thecushion member 168.

FIG. 9 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure.

Redundant features of the display device 500 according to the otherembodiment of the present disclosure and the display device 300according to the other embodiment of the present disclosure may beomitted merely for the sake of convenience of explanation.

The features of the electroluminescence display panel 110, thefingerprint sensor 140, the support substrate 160, the first adhesivemember 150-1 and the second adhesive member 152 of the display device500 according to the other embodiment of the present disclosure may beimplemented substantially the same as the features of theelectroluminescence display panel 110, the fingerprint sensor 140, thesupport substrate 160, the first adhesive member 150-1 and the secondadhesive member 152 of the display device 300 according to the otherembodiment of the present disclosure. Thus, the redundant descriptionsmay be omitted merely for convenience of explanation.

The features of the light-shield member 162 of the display device 500according to the other embodiment of the present disclosure may beimplemented substantially the same as the features of the light-shieldmember 162 of the display device 400 according to the other embodimentof the present disclosure. Thus, the redundant descriptions may beomitted merely for convenience of explanation.

The display device 500 according to the other embodiment of the presentdisclosure may be configured to include the light-shield member 162disposed between the support substrate 160 and the fingerprint sensor140.

According to the above-described configuration, even if the fingerprintsensor 140 is attached to the light-shield member 162, the occurrence ofshadow-mura in the electroluminescence display panel 110 can besuppressed and the deterioration of signal sensitivity of the ultrasonictransmission and reception channel can be minimized. In addition, theflatness of the electroluminescence display panel 110 can be improved bythe light-shield member 162.

According to the above-described configuration, the first adhesivemember 150-1 can minimize the deterioration of the ultrasonictransmission and reception characteristics, and the first adhesivemember 150-1 can be further provided to the area other than theattachment area of the fingerprint sensor 140, thereby some componentsother than the fingerprint sensor 140 may be attached by the firstadhesive member 150-1.

FIG. 10 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure.

Redundant features of the display device 600 according to the otherembodiment of the present disclosure and the display device 400according to the other embodiment of the present disclosure may beomitted merely for the sake of convenience of explanation.

The features of the electroluminescence display panel 110, thefingerprint sensor 140, the support substrate 160, the first adhesivemember 150, the second adhesive member 152, and the light-shield member162 of the display device 600 according to the other embodiment of thepresent disclosure may be implemented substantially the same as thefeatures of the electroluminescence display panel 110, the fingerprintsensor 140, the support substrate 160, the first adhesive member 150,the second adhesive member 152, and the light-shield member 162 of thedisplay device 400 according to the other embodiment of the presentdisclosure. Thus, the redundant descriptions may be omitted merely forconvenience of explanation.

When the fingerprint sensor 140 is disposed under the rear side of theelectroluminescence display panel 110, the heat dissipationcharacteristic of the rear side of the electroluminescence display panel110 may be varied by the arrangement of the fingerprint sensor 140. Inaddition, it is also observed that a residual image may be generated onthe displayed image due to the temperature deviation of theelectroluminescence display panel 110 according to the heat radiationdeviation.

Accordingly, the display device 600 according to the other embodiment ofthe present disclosure may be configured to include the heat dissipationmember 164 disposed under the rear surface of the light-shield member162.

The heat dissipation member 164 may be configured to surround thefingerprint sensor 140 and overlap a portion of the display area AA toperform the function of a heat sink for the electroluminescence displaypanel 110. For example, the heat dissipation member 164 may beconfigured to substantially cover the display area AA excluding theopening OP.

In addition, an adhesive member may be further included between the heatdissipation member 164 and the light-shield member 162. However, itshould be noted that since the adhesive member corresponding to theregion other than the ultrasonic transmission and reception channel ofthe fingerprint sensor 140 does not substantially affect the performanceof the ultrasonic transmission and reception channel. Therefore, theregion other than the ultrasonic transmission and reception channel ofthe fingerprint sensor 140 may be omitted for convenience ofexplanation.

In addition, the heat dissipation member 164 may be configured to havean opening OP corresponding to the fingerprint sensor 140. The openingOP may have gaps GAP1 and GAP2 spaced apart from the fingerprint sensor140 by a particular distance. According to the above-describedconfiguration, the heat dissipation member 164 can be separated from thefirst adhesive member 150 regardless of the thickness or the step thefirst adhesive member 150. Therefore, delamination or peel-off of theheat dissipation member 164 due to the level of the first adhesivemember 150 may be suppressed.

The heat dissipation member 164 may be made of a material having a highthermal conductivity. For example, the heat dissipation member 164 maybe made of a material such as metal, graphite, and/or graphene. Forexample, the thickness of the heat dissipation member 164 may be 50 μmto 100 μm. However, the present disclosure is not limited thereto.

According to the above-described configuration, the temperaturedeviation between the fingerprint sensor 140 and periphery of thefingerprint sensor 140 can be reduced by the heat dissipation member164. Therefore, it is possible to reduce the occurrence of imageretention due to the attachment of the fingerprint sensor 140.

In addition, when the heat dissipation member 164 is a conductivematerial, the heat dissipation member 164 can be electrically grounded.However, the present disclosure is not limited thereto.

On the other hand, the heat dissipation member 164-1 may not be bondedas a separate element. By improving a particular component, such as alayer, a structure and/or its material to improve its heat dissipationfunction, thereby substituting the heat dissipation member. In suchcase, the light-shield member 162 may substitute the heat dissipationmember.

FIG. 11 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure.

Redundant features of the display device 700 according to the otherembodiment of the present disclosure and the display device 600according to the other embodiment of the present disclosure may beomitted merely for the sake of convenience of explanation.

The features of the electroluminescence display panel 110, thefingerprint sensor 140, the support substrate 160, the first adhesivemember 150, the second adhesive member 152, and the light-shield member162 of the display device 700 according to the other embodiment of thepresent disclosure may be implemented substantially the same as thefeatures of the electroluminescence display panel 110, the fingerprintsensor 140, the support substrate 160, the first adhesive member 150,the second adhesive member 152, and the light-shield member 162 of thedisplay device 600 according to the other embodiment of the presentdisclosure. Thus, the redundant descriptions may be omitted merely forconvenience of explanation.

The heat dissipation member 164-1 of the display device 700 according tothe other embodiment of the present disclosure may be implementedsubstantially the same material as the heat dissipation member 164 ofthe display device 600 according to the other embodiment of the presentdisclosure. Thus, the redundant descriptions may be omitted merely forconvenience of explanation.

The display device 700 according to the other embodiment of the presentdisclosure may be configured to include the heat dissipation member164-1 below the rear side of the light-shield member 162. The heatdissipation member 164-1 may be configured to cover the fingerprintsensor 140. That is, the heat dissipation member 164-1 may be configuredto overlap with the fingerprint sensor 140.

For example, the heat dissipation member 164-1 may be configured toadhere to the light-shield member 162 while covering the fingerprintsensor 140.

For example, the heat dissipation member 164-1 may be configured topackage the fingerprint sensor 140. Further, the heat dissipation member164-1 may be attached only to the rear side of the fingerprint sensor140 without contacting the light-shield member 162. That is, a portionof the heat dissipation member 164-1 that is in contact with thefingerprint sensor 140 is not in contact with the light-shield member162.

According to the above-described configuration, the heat dissipationmember 164-1 can heat sink the heat generated from theelectroluminescence display panel 110 and the fingerprint sensor 140.According to the above-described configuration, the temperaturedeviation around the fingerprint sensor 140 and the fingerprint sensor140 can be reduced by the dissipation member 164-1. Therefore, it ispossible to reduce the occurrence of a residual image due to atemperature deviation due to the attachment of the fingerprint sensor140. The position, thickness, area, material, and the like of the heatdissipation member 164-1 may be variously modified according to thetype, size, use environment, purpose of use, and the like of the displaydevice including the fingerprint sensor 140.

FIG. 12 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure.

Redundant features of the display device 800 according to the otherembodiment of the present disclosure and the display device 600according to the other embodiment of the present disclosure may beomitted merely for the sake of convenience of explanation.

The features of the electroluminescence display panel 110, thefingerprint sensor 140, the support substrate 160, the first adhesivemember 150, the second adhesive member 152, the light-shield member 162,the heat dissipation member 164 of the display device 800 according tothe other embodiment of the present disclosure may be implementedsubstantially the same as the features of the electroluminescencedisplay panel 110, the fingerprint sensor 140, the support substrate160, the first adhesive member 150, the second adhesive member 152, thelight-shield member 162, the heat dissipation member 164 of the displaydevice 600 according to the other embodiment of the present disclosure.Thus, the redundant descriptions may be omitted merely for convenienceof explanation.

When the fingerprint sensor 140 is disposed under the rear surface ofthe electroluminescence display panel 110, the electroluminescencedisplay panel 110 and the fingerprint sensor 140 may be damaged by anexternal impact due to an arrangement of the fingerprint sensor 140.

In addition, the fingerprint sensor 140 may be constituted by asubstrate having a high Young's modulus value for transmittingultrasonic waves for fingerprint transmission, for example, ultrasonicwaves having a frequency of 10 MHz or more. Therefore, the fingerprintsensor 140 may be damaged by an external impact.

The display device 800 according to the other embodiment of the presentdisclosure may be configured to include a cushion member 168 disposedunder the rear surface of the heat dissipation member 164. The cushionmember 168 of the present disclosure may refer to a member configured toabsorb an impact. For example, the cushion member 168 may be a materialhaving a high elasticity or having a deformable property to absorb ashock and having an excellent restoration ability.

The cushion member 168, surrounds the fingerprint sensor 140, may beconfigured to overlap with at least a portion of the display area AA toabsorb a shock transmitted to the electroluminescence display panel 110and the fingerprint sensor 140. For example, the cushion member 168 maybe configured to cover the entire display area AA except for the openingOP. The cushion member 168 may absorb the impact that may be transmittedthrough the electroluminescence display panel 110, thereby protectingthe ultrasonic fingerprint sensor 140. The cushion member 168 may bemade of a light absorbing material. Therefore, the shadow-mura may be bereduced by the cushion member 168 as well.

The cushion member 168 may be configured not to be disposed between thefingerprint sensor 140 and the electroluminescence display panel 110 ifthe ultrasonic wave, dedicated for fingerprint recognition, having atleast 10 MHz of frequency. Ultrasonic waves can be absorbed if thecushion member 168 is disposed in the middle of the ultrasonictransmission and reception channel.

In addition, an adhesive member may be further included between thecushion member 168 and the heat dissipation member 164. However, itshould be noted that since the adhesive member corresponding to theregion other than the ultrasonic transmission and reception channel ofthe fingerprint sensor 140 does not substantially affect the performanceof the ultrasonic transmission and reception channel. Therefore, theregion other than the ultrasonic transmission and reception channel ofthe fingerprint sensor 140 may be omitted for convenience ofexplanation.

In addition, the cushion member 168 may be configured to have an openingcorresponding to the size (e.g., width and length) of the fingerprintsensor 140. The opening may have gaps spaced a certain distance from thefingerprint sensor 140. Since the opening and the gaps are illustratedin FIG. 10, a redundant description will be omitted for convenience ofexplanation. According to the above-described configuration, the cushionmember 168 can be separated from the first adhesive member 150regardless of the step of the first adhesive member 150. Therefore,peeling of the cushion member 168 due to the step of the first adhesivemember 150 can be suppressed.

In addition, the light-shield member 162 may be configured to shield theopening of the cushion member 168 to shield the rear side of theelectroluminescence display panel 110 from light.

The cushion member 168 may be made of an impact-absorbing material. Forexample, the cushion member 168 may be made of a material such as foamtape and/or rubber. For example, the thickness of the cushion member 168may be 60 μm to 200 μm. However, the present disclosure is not limitedthereto.

For example, according to the above-described configuration, when thecushion member 168 is a foam tape, even if an impact is transmitted tothe electroluminescence display panel 110, it is possible to reduce theimpact transmitted from the display panel 110 to the fingerprint sensor140 by the cushion member 168. Therefore, when the electroluminescencedisplay panel 110 is shocked, the fingerprint sensor 140 may beprotected from being damaged.

In addition, when the cushion member 168 is a foam tape, the foam tapecan absorb ultrasonic waves for fingerprint recognition because itcontains a plurality of bubbles. Therefore, it is possible to absorb theunnecessary transmission of the ultrasonic wave to the area other thanthe fingerprint recognition area FDA of the electroluminescence displaypanel 110. Therefore, unnecessary ultrasonic noise can be reduced.However, the present disclosure is not limited thereto. Therefore, thecushion member 168 according to the embodiments of the presentdisclosure may be referred to as an ultrasonic absorbing member forfingerprint recognition.

The cushion member 168 may be positioned under the rear side of thesupport substrate 160 and surround the fingerprint sensor 140. A portionof the outer periphery of the light-shield member 162 may be overlappedwith the cushion member 168.

In some cases, the cushion member 168 and the heat dissipation member164 may be embodied as one member rather than separate members. That is,the present disclosure can be realized as a material that can integratea cushion function and a heat dissipation function together with asingle film or layer type member. Such an integrated functional member

The position, thickness, area, material, and the like of such anintegrated functional member may be variously modified according to thetype, size, use environment, purpose of use, and the like of the displaydevice including the fingerprint sensor 140.

FIG. 13 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure.

Redundant features of the display device 900 according to the otherembodiment of the present disclosure and the display devices 500, 800according to the embodiments of the present disclosure may be omittedmerely for the sake of convenience of explanation.

The features of the electroluminescence display panel 110, thefingerprint sensor 140, the support substrate 160, the first adhesivemember 150-1, the second adhesive member 152, and the light-shieldmember 162 of the display device 900 according to the other embodimentof the present disclosure may be implemented substantially the same asthe features of the electroluminescence display panel 110, thefingerprint sensor 140, the support substrate 160, the first adhesivemember 150-1, the second adhesive member 152, and the light-shieldmember 162 of the display device 500 according to the other embodimentof the present disclosure. Thus, the redundant descriptions may beomitted merely for convenience of explanation.

The cushion member 168 of the display device 900 according to the otherembodiment of the present disclosure may be implemented substantiallythe same material as the cushion member 168 of the display device 800according to the other embodiment of the present disclosure. Thus, theredundant descriptions may be omitted merely for convenience ofexplanation.

The display device 900 according to the other embodiment of the presentdisclosure may be configured to include the heat dissipation member164-1 under the rear surface of the cushion member 168. The heatdissipation member 164-2 may be configured to cover the fingerprintsensor 140. That is, the heat dissipation member 164-1 may be configuredto overlap with the fingerprint sensor 140.

For example, the heat dissipation member 164-2 may be configured to bein direct contact with the cushion member 168 and the fingerprint sensor140.

According to the above-described configuration, the heat dissipationmember 164-1 may transfer heat generated in the fingerprint sensor 140.Further, a system circuitry connected to the electroluminescence displaypanel 110 may be further disposed under the rear surface of the heatdissipation member 164-1. Further, a frame for supporting theelectroluminescence display panel 110 and the system circuitry may befurther disposed between the electroluminescence display panel 110 andthe system circuitry. In this case, the heat dissipation member 164-1can transfer heat of the fingerprint sensor 140 toward the frame.According to the above-described configuration, the temperaturedeviation around the fingerprint sensor 140 and the fingerprint sensor140 can be reduced by the heat dissipation member 164-1. Therefore, itis possible to reduce the occurrence of a residual image due to atemperature deviation due to the attachment of the fingerprint sensor140.

In addition, the level difference between the fingerprint sensor 140 andthe heat dissipation member 164-2 can be reduced by the cushion member168. According to the above-described configuration, as compared withthe heat dissipation member 164-1 of the display device 700 according tothe other embodiment of the present disclosure, the possibility ofgenerating a tension that can be generated by the heat dissipationmember 164-2 can be reduced.

In addition, when the heat dissipation member 164-1 of the displaydevice 700 according to the other embodiment of the present disclosureis adhered, a pressure may be applied to the fingerprint sensor 140 dueto a misalign error in the adhesion process. In such case, thefingerprint sensor 140 may apply unwanted pressure to theelectroluminescence display panel 110. Accordingly, the flatness of theelectroluminescence display panel 110 may be lowered, and the pressedmark may be visually recognized.

However, when the step between the fingerprint sensor 140 and the heatdissipation member 164-2 is minimized by the cushion member 168, thepressure that can be applied to the fingerprint sensor 140 when adheringthe heat dissipation member 164-2 can be minimized. Therefore,occurrence of a flatness defect of the electroluminescence display panel110 can be reduced.

FIG. 14 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure.

Redundant features of the display device 1000 according to the otherembodiment of the present disclosure and the display device 200according to another embodiment of the present disclosure may be omittedmerely for the sake of convenience of explanation.

The features of the electroluminescence display panel 110, thefingerprint sensor 140, the support substrate 160, and the secondadhesive member 152, of the display device 1000 according to the otherembodiment of the present disclosure may be implemented substantiallythe same as the features of the electroluminescence display panel 110,the fingerprint sensor 140, the support substrate 160, and the secondadhesive member 152 of the display device 200 according to anotherembodiment of the present disclosure. Thus, the redundant descriptionsmay be omitted merely for convenience of explanation.

The electromagnetic interference (EMI) generated by the scan pulse andthe data signal of the electroluminescence display panel 110 may becomea noise to the fingerprint sensor 140. Further, the electromagneticinterference generated by the operation of the fingerprint sensor 140may become a noise of the electroluminescence display panel 110.

Particularly, the ultrasonic fingerprint sensors may require a highvoltage to generate a high frequency of ultrasonic wave. Accordingly,electromagnetic interference can be generated. However, the presentdisclosure is not limited to the driving voltage level of thefingerprint sensor 140.

Accordingly, the electroluminescence display panel 110 may bedeteriorated in image quality due to the electromagnetic interference ofthe fingerprint sensor 140, but also, at the same time, the fingerprintsensor 140 may be deteriorated in fingerprint recognition sensitivitydue to the electromagnetic interference of the electroluminescencedisplay panel 110.

Thus, the display device 1000 according to the other embodiment of thepresent disclosure may be configured to include the EMI shield member170 disposed between the support substrate 160 and the fingerprintsensor 140.

A display device 1000 according to the other embodiment of the presentdisclosure may include a substrate, a display area including a pluralityof pixels on the substrate and having a fingerprint recognition areaFDA, a support substrate 160 under the rear surface of the substrate, afingerprint sensor 140 under the rear surface of the support substrate160 in accordance with the fingerprint recognition area FDA, and an EMIshield member 170 disposed between the support substrate 160 and thefingerprint sensor 140.

A display device 1000 according to the other embodiment of the presentdisclosure may include an electroluminescence display panel 110including a plurality of pixels PXL on a flexible substrate, a supportsubstrate 160 supporting the electroluminescence display panel 110, anda EMI shield member 170 under a rear surface of the support substrate160 configured to transmit an ultrasonic wave of a particular frequency.

A display device 1000 according to the other embodiment of the presentdisclosure may include a substrate on which a plurality of pixels PXLare arranged thereon, a see-through support substrate 160 under a rearsurface of the substrate, a cushion member 168, including an opening,under a rear surface of the see-through support substrate 160, anultrasonic fingerprint sensor 140 at the opening, and an EMI shieldmember, overlaps with the opening, configured to shield anelectromagnetic interference noise through the see-through supportsubstrate 160 that may affect the ultrasonic fingerprint sensor 140.

A display device 1000 according to the other embodiment of the presentdisclosure may include an electroluminescence display panel 110, afingerprint sensor 140 under a rear surface of the electroluminescencedisplay panel 110, and an EMI shield member 170 that is a part of anultrasonic transmission and reception channel of the fingerprint sensor140, configured to shield a plurality of electrical signals generated inthe electroluminescence display panel 110, thereby improving the imagequality of the electroluminescence display panel 110.

The EMI shield member 170 may be configured to shield at least a regionwhere the fingerprint sensor 140 and the electroluminescence displaypanel 110 are overlapped. For example, the EMI shield member 170 may beconfigured to shield at least the fingerprint recognition area FDA.However, the present disclosure is not limited thereto. Further, the EMIshield member 170 may be configured to shield the fingerprintrecognition area FDA and at least a portion of the display area AA.Furthermore, the EMI shield member 170 may be configured to shield thedisplay area AA and the non-display area NA. That is, the EMI shieldmember 170 may be configured to shield at least the electromagneticinterference noise between the electroluminescence display panel 110 andthe fingerprint sensor 140 by shielding at least the fingerprintrecognition area FDA.

The fingerprint sensor 140 may be fixed to the rear side of the EMIshield member 170 and output ultrasonic waves of a specific frequencytoward the EMI shield member 170. The control unit of the fingerprintsensor 140 may generate an ultrasonic wave having a specific frequencyband such as 10 MHz to 15 MHz to allow the ultrasonic wave to passthrough the EMI shield member 170 disposed under the rear side of theelectroluminescence display panel 110 such that the ultrasonic wave canbe transmitted and received through the Tx electrodes 141 and the Rxelectrodes 143.

The EMI shield member 170 may be made of a conductive material. Forexample, the EMI shield member 170 may comprise metallic particles ormay be a metal foil. The EMI shield member 170 may be coated directly atthe rear side of the support substrate 160 or may be bonded togetherthrough a separate bonding member. When the EMI shield member 170 is aconductive ink, the thickness of the EMI shield member 170 may be 300 nmor less. For example, the thickness of the EMI shield member 170 may bebetween 25 nm and 300 nm. The EMI shield member 170 may be a metal layerand may be configured to shield external light transmitted through theelectroluminescence display panel 110.

As the thickness of the EMI shield member 170 becomes thicker than 300nm, the shielding performance of the electromagnetic interference noisemay be reduced. It has also been recognized that when the thickness ofthe EMI shield member 170 is thinner than 25 nm, the shieldingperformance of the electromagnetic interference performance may bereduced.

Accordingly, the EMI shield member 170 of the display device 100according to the other embodiment of the present disclosure may beconfigured to include copper (Cu), and the thickness may be 150 nm to250 nm. However, the present disclosure is not limited thereto.

For example, the EMI shield member 170 may be a conductive ink. The EMIshield member 170 may be coated or printed directly under the rear sideof the support substrate 160.

For example, the EMI shield member 170 may be a thin metal film. The EMIshield member 170 may be deposited on the support substrate 160.

For example, when the EMI shield member 170 is formed directly on thesupport substrate 160, since an adhesive member is unnecessary, anadditional adhesive member may not be required even if the EMI shieldmember 170 is added. Therefore, it is possible to improve the imagequality of the electroluminescence display panel 110 and the fingerprintrecognition sensitivity of the fingerprint sensor 140 while maintainingthe signal sensitivity of the fingerprint sensor 140.

For example, the electroluminescence display panel 110 may be configuredto include a fingerprint recognition area FDA corresponding to afingerprint sensor 140 and an EMI shield member 170, overlapping withthe fingerprint recognition area FDA, having an area larger than an areaof the fingerprint sensor 140.

In addition, the EMI shield member 170 may be grounded. When the EMIshield member 170 is electrically grounded, the shielding performancecan be improved. In addition, when the EMI shield member 170 isgrounded, the transistor TFT of the electroluminescence display panel110 and the EMI shield member 170 may generate parasitic capacitance.Therefore, in order to minimize the parasitic capacitance of the EMIshield member 170, the distance between the EMI shield member 170 andthe electroluminescence display panel 110 may be at least 20 μm.Specifically, the distance between the EMI shield member 170 and the TFTof the electroluminescence display panel 110 may be at least 20 μm.Therefore, even if the EMI shield member 170 is included in the displaydevice 1000, the parasitic capacitance problem can be minimized.

According to the above-described configuration, as the increase inthickness can be minimized, electromagnetic interference noise generatedbetween the fingerprint sensor 140 and the electroluminescence displaypanel 110 can be shielded by the EMI shield member 170, thereby thefingerprint sensing performance of the fingerprint sensor 140 and theimage quality of the electroluminescence display panel 110 can beimproved at the same time.

Alternatively, the EMI shield member 170 may be integrated into anotherelement, for example, a support substrate 160, to provide a shieldingability rather than being implemented as a separate component.

Whether to implement the EMI shield member 170 as a separate element, asan integrated element with other element or both can be variouslymodified according to the type, size, use environment, purpose of use,and the like of the display device including the fingerprint sensor 140.

FIG. 15 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure.

Redundant features of the display device 1100 according to the otherembodiment of the present disclosure and the display devices 300, 1000according to the other embodiments of the present disclosure may beomitted merely for the sake of convenience of explanation.

The features of the electroluminescence display panel 110, thefingerprint sensor 140, the support substrate 160, the first adhesivemember 150-1, and the second adhesive member 152, of the display device1100 according to the other embodiment of the present disclosure may beimplemented substantially the same as the features of theelectroluminescence display panel 110, the fingerprint sensor 140, thesupport substrate 160, the first adhesive member 150-1, and the secondadhesive member 152 of the display devices 300, 1000 according to theother embodiments of the present disclosure. Thus, the redundantdescriptions may be omitted merely for convenience of explanation.

The display device 1100 according to the other embodiment of the presentdisclosure may be configured to include the EMI shield member 170disposed between the support substrate 160 and the first adhesive member150-1.

The EMI shield member 170 may be configured to shield at least the areawhere the fingerprint sensor 140 and the electroluminescence displaypanel 110 overlap. For example, the EMI shield member 170 may beconfigured to shield at least the fingerprint recognition area FDA.However, the present disclosure is not limited thereto, and the EMIshield member 170 may be configured to shield at least a part of thefingerprint recognition area FDA and the display area AA. Further, theEMI shield member 170 may be configured to shield the display area AAand the non-display area NA.

According to the above-described configuration, the electromagneticinterference noise generated between the fingerprint sensor 140 and theelectroluminescence display panel 110 may be shielded by the EMI shieldmember 170. Accordingly, the fingerprint sensing performance of thefingerprint sensor 140 and the image quality of the electroluminescencedisplay panel 110 can be improved at the same time.

In addition, since the first adhesive member 150-1 can be provided inother areas except for the fingerprint sensor 140, components other thanthe fingerprint sensor 140 can be adhered by the first adhesive member150-1.

In some cases, a metallic material may be included in the first adhesivemember 150-1 to substitute the EMI shield member 170 or to provide anadditional shielding ability to the first adhesive member 150-1. Thatis, the EMI shield member may be variously modified according to thetype, size, use environment, purpose of use, and the like of the displaydevice including the fingerprint sensor 140.

FIG. 16 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure.

Redundant features of the display device 1200 according to the otherembodiment of the present disclosure and the display devices 400, 1000according to the other embodiments of the present disclosure may beomitted merely for the sake of convenience of explanation.

The features of the electroluminescence display panel 110, thefingerprint sensor 140, the support substrate 160, the first adhesivemember 150, the second adhesive member 152, and the light-shield member162, and the EMI shield member 170 of the display device 1100 accordingto the other embodiment of the present disclosure may be implementedsubstantially the same as the features of the electroluminescencedisplay panel 110, the fingerprint sensor 140, the support substrate160, the first adhesive member 150, the second adhesive member 152, andthe light-shield member 162, and the EMI shield member 170 of thedisplay devices 400, 1000 according to the other embodiments of thepresent disclosure. Thus, the redundant descriptions may be omittedmerely for convenience of explanation.

When the EMI shield member 170 is a metallic material, it may have areflection characteristic with respect to visible light, and when theexternal light is reflected by the EMI shield member having a reflectioncharacteristic, the image quality of the electroluminescence displaypanel 110 may be deteriorated.

The display device 1200 according to the other embodiment of the presentdisclosure may include the light-shield member 162 and the EMI shieldmember 170 which are sequentially stacked between the support substrate160 and the fingerprint sensor 140. That is, EM the shield member 170 ispositioned under the rear surface of the light-shield member 162.

In addition, if the light-shield member 162 is positioned under the rearsurface of the EMI shield member 170, electromagnetic interference noisemay be reduced, but it may be difficult to improve the external lightreflection problem as described-above.

According to the above-described configuration, the problem ofdeterioration in image quality due to external light due to the EMIshield member 170 can be suppressed by disposing the light-shield member162 between the EMI shield member 170 and the electroluminescencedisplay panel 110. That is, the light-shield member 162 can absorb atleast a portion of the external light. At the same time, theelectromagnetic interference noise generated between the fingerprintsensor 140 and the electroluminescence display panel 110 can be shieldedby the EMI shield member 170. Accordingly, the fingerprint sensingperformance of the fingerprint sensor 140 and the image quality of theelectroluminescence display panel 110 can be improved at the same time.

Herein, the light-shield member 162 and the EMI shield member 170 aredescribed as separate elements but it may be realized as a single filmor layer that integrate a light-shielding function and an EMI shieldingfunction together. That is, the integrated shield member may bevariously modified according to the type, size, use environment, purposeof use, and the like of the display device including the fingerprintsensor 140.

FIG. 17 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure.

Redundant features of the display device 1300 according to the otherembodiment of the present disclosure and the display devices 500, 1000according to the other embodiments of the present disclosure may beomitted merely for the sake of convenience of explanation.

The features of the electroluminescence display panel 110, thefingerprint sensor 140, the support substrate 160, the first adhesivemember 150-1, the second adhesive member 152, the light-shield member162, and the EMI shield member 170 of the display device 1100 accordingto the other embodiment of the present disclosure may be implementedsubstantially the same as the features of the electroluminescencedisplay panel 110, the fingerprint sensor 140, the support substrate160, the first adhesive member 150-1, the second adhesive member 152,the light-shield member 162, and the EMI shield member 170 of thedisplay devices 500, 1000 according to the other embodiments of thepresent disclosure. Thus, the redundant descriptions may be omittedmerely for convenience of explanation.

The display device 1300 according to the other embodiment of the presentdisclosure may be configured to include the light-shield member 162 andthe EMI shield member 170 which are sequentially stacked between thesupport substrate 160 and the fingerprint sensor 140. That is, the EMIshield member 170 is under the rear surface of the light-shield member162.

The image quality degradation due to the external light due to the EMIshield member 170 can be suppressed by the light-shield member 162disposed between the EMI shield member 170 and the electroluminescencedisplay panel 110. At the same time, the electromagnetic interferencenoise generated between the fingerprint sensor 140 and theelectroluminescence display panel 110 is shielded by the EMI shieldmember 170, thereby improving the fingerprint sensing performance of thefingerprint sensor 140 and the image quality of the electroluminescencedisplay panel 110 at the same time.

In addition, since the first adhesive member 150-1 can be provided inother areas except for the fingerprint sensor 140, components other thanthe fingerprint sensor 140 also can be adhered.

FIG. 18 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure.

Redundant features of the display device 1400 according to the otherembodiment of the present disclosure and the display devices 800, 1200according to the other embodiments of the present disclosure may beomitted merely for the sake of convenience of explanation.

The features of the electroluminescence display panel 110, thefingerprint sensor 140, the support substrate 160, the first adhesivemember 150, the second adhesive member 152, the light-shield member 162,the cushion member 168, and the EMI shield member 170 of the displaydevice 1400 according to the other embodiment of the present disclosuremay be implemented substantially the same as the features of theelectroluminescence display panel 110, the fingerprint sensor 140, thesupport substrate 160, the first adhesive member 150, the secondadhesive member 152, the light-shield member 162, the cushion member168, and the EMI shield member 170 of the display devices 800, 1200according to the other embodiments of the present disclosure. Thus, theredundant descriptions may be omitted merely for convenience ofexplanation.

When the cushion member 168 is configured to surround the fingerprintsensor 140 and the third adhesive member 154, arranged between thecushion member 168 and the EMI shield member 170, configured to surroundthe fingerprint sensor 140 may not affect in the ultrasonic transmissionand reception channel of the fingerprint sensor 140. Thus, it isrecognized that the ultrasonic transmission characteristics may beignored. That is, the third adhesive member 154, which can be disposedin an area other than the ultrasonic transmission and reception channelof the fingerprint sensor 140, does not substantially affect theultrasonic transmission and reception channel. Therefore, the Young'smodulus value and the thickness of the third adhesive member 154 may notbe limited.

Accordingly, the display device 1400 according to the other embodimentof the present disclosure may be configured to include the thirdadhesive member 154 disposed between the cushion member 168 and the EMIshield member 170.

According to the above-described configuration, the problem ofdeterioration in image quality due to external light due to the EMIshield member 170 can be suppressed by the light-shield member 162disposed between the EMI shield member 170 and the electroluminescencedisplay panel 110. Further, unnecessary dispersion of ultrasonic wavesfrom the fingerprint sensor 140 can be absorbed by the cushion member168. Further, the electromagnetic interference noise generated betweenthe fingerprint sensor 140 and the electroluminescence display panel 110can be shielded by the EMI shield member 170. Furthermore, the Young'smodulus and the thickness of the third adhesive member 154 may not belimited thereto.

In some cases, the cushion member 168 and the EMI shield member 170 maybe realized as an integrated member. That is, the integrated member maybe realized as a single film or layer that integrates a cushion functionand an EMI shielding function together. That is, the position,thickness, area, material, and the like of the integrated member may bevariously modified according to the type, size, use environment, purposeof use, and the like of the display device including the fingerprintsensor 140.

FIG. 19 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure.

Redundant features of the display device 1500 according to the otherembodiment of the present disclosure and the display devices 800, 1300according to the other embodiments of the present disclosure may beomitted merely for the sake of convenience of explanation.

The features of the electroluminescence display panel 110, thefingerprint sensor 140, the support substrate 160, the first adhesivemember 150-1, the second adhesive member 152, the light-shield member162, the cushion member 168, and the EMI shield member 170 of thedisplay device 1500 according to the other embodiment of the presentdisclosure may be implemented substantially the same as the features ofthe electroluminescence display panel 110, the fingerprint sensor 140,the support substrate 160, the first adhesive member 150-1, the secondadhesive member 152, the light-shield member 162, the cushion member168, and the EMI shield member 170 of the display devices 800, 1300according to the other embodiments of the present disclosure. Thus, theredundant descriptions may be omitted merely for convenience ofexplanation.

A display device 1500 according to the other embodiment of the presentdisclosure may include a light-shield member 162, an EMI shield member170, a first adhesive member 150-1 and a cushion member 168 configuredto surround the fingerprint sensor 140.

According to the above-described configuration, the problem ofdeterioration in image quality due to external light due to the EMIshield member 170 can be suppressed by the light-shield member 162disposed between the EMI shield member 170 and the electroluminescencedisplay panel 110. Further, unnecessary transmission of ultrasonic wavesfrom the fingerprint sensor 140 can be reduced by the cushion member 168and electromagnetic interference between the fingerprint sensor 140 andthe electroluminescence display panel 110 can be shielded by the EMIshield member 170. Since the first adhesive member 150-1 can be providedin a periphery area of the fingerprint sensor 140, components other thanthe fingerprint sensor 140 can be adhered.

FIG. 20 and FIG. 21 are cross-sectional views schematically illustratinga cross section A′-A″ corresponding to a fingerprint recognition area ofa display device including an electroluminescence display panel capableof providing a fingerprint recognition function according to the otherembodiments of the present disclosure.

Redundant features of the display devices 1600, 1700 according to theother embodiments of the present disclosure and the display devices 700,800, 900, 1400 according to the other embodiments of the presentdisclosure may be omitted merely for the sake of convenience ofexplanation.

The features of the electroluminescence display panel 110, thefingerprint sensor 140, the support substrate 160, the first adhesivemember 150, 150-1, the second adhesive member 152, the light-shieldmember 162, the heat dissipation member 164, 164-1, the cushion member168, and the EMI shield member 170 of the display devices 1600, 1700according to the other embodiments of the present disclosure may beimplemented substantially the same as the features of theelectroluminescence display panel 110, the fingerprint sensor 140, thesupport substrate 160, the first adhesive member 150, 150-1, the secondadhesive member 152, the light-shield member 162, the heat dissipationmember 164, 164-1, the cushion member 168, and the EMI shield member 170of the display devices 800, 1300 according to the other embodiments ofthe present disclosure. Thus, the redundant descriptions may be omittedmerely for convenience of explanation.

The display device 1600 according to the other embodiment of the presentdisclosure is characterized in that the heat dissipation member 164 isdisposed under the rear side of the cushion member 168.

The display device 1700 according to the other embodiment of the presentdisclosure, the cushion member 168-1 is configured to cover the displayarea and the fingerprint sensor 140, and the heat dissipation member164-1 is configured to correspond to the cushion member 168-1 under therear surface of the cushion member 168-1.

According to the above-described configuration, a generation ofshadow-mura problem can be suppressed, an electromagnetic interferencenoise can be shielded, an impact applied to the fingerprint sensor 140can be absorbed, and an unnecessary transmission of ultrasonic wavesfrom the fingerprint sensor 140 can be reduced.

In addition, the ultrasonic waves output from the fingerprint sensor 140can be transmitted toward to the rear side of the fingerprint sensor.Referring to FIG. 21, when the cushion member 168-1 is configured tocover the rear side of the fingerprint sensor 140, a portion of theultrasonic wave transmitted toward a frame disposed under the rearsurface of the fingerprint sensor 140 for supporting a system circuitryand an electroluminescence display panel 110 can be absorbed by thecushion member 168-1. Therefore, unnecessary transmission of theultrasonic waves of the fingerprint sensor 140 toward the rear side canbe reduced.

In some embodiments, the cushion member may be separated into aplurality of pieces, and a cushion member composed of a plurality ofpieces may be configured to surround the fingerprint sensor 140.

In some cases, the cushion member 168-1 and the heat dissipation member164-1 may be realized as an integrated member. That is, the integratedmember may be realized as a single film or layer that integrates acushion function and a heat sinking function together. That is, theposition, thickness, area, material, and the like of the integratedmember may be variously modified according to the type, size, useenvironment, purpose of use, and the like of the display deviceincluding the fingerprint sensor 140.

FIG. 22 to FIG. 27 are cross-sectional views schematically illustratinga cross section A′-A″ corresponding to a fingerprint recognition area ofa display device including an electroluminescence display panel capableof providing a fingerprint recognition function according to the otherembodiments of the present disclosure.

Redundant features of the display devices 1800, 1900, 2000, 2100, 2200,2300 according to the other embodiments of the present disclosure andthe display devices as illustrated in FIG. 1 to FIG. 21 according to theother embodiments of the present disclosure may be omitted merely forthe sake of convenience of explanation.

The display devices 1800, 1900, 2000, 2100, 2200, 2300 according to theembodiments of the present disclosure may include a light and EMI shieldmember 172, for shielding external light and electromagneticinterference noise, disposed between the electroluminescence displaypanel 110 and the fingerprint sensor 140.

The light and EMI shield member 172 may refer to a multi-functionalmember configured to perform the functions of the light-shield member162 and the EMI shield member 170. Further, the light and EMI shieldmember 172 may be applied as an alternative embodiment for someembodiments to which the light-shield member 162 and the EMI shieldmember 170 are applied.

According to the above-described configuration, the embodimentsincluding the light-shield member 162 and the EMI shield member 170 maybe embodied as alternative embodiments in which the light and EMI shieldmember 172 is substituted, thereby reducing the cost.

The light and EMI shield member 172 may be configured to have a lightabsorbing property and a conductivity at the same time. For example, thelight and EMI shield member 172 may include graphite, carbon, graphene,metal particles, and the like. The light and EMI shield member 172 mayhave a visible light absorption rate of 80% or more and a sheetresistance of 30 Ω/Sq/mil or less. The thickness of the light and EMIshield member 172 may be 50 nm to 300 nm. However, the presentdisclosure is not limited thereto. If the thickness of the light and EMIshield member 172 is 300 nm or more, the shielding performance may bedeteriorated. If the thickness of the light and EMI shield member 172 isless than 50 nm, the visible light absorption rate may be lowered.

According to the above-described configuration, the light and EMI shieldmember 172 can be applied to minimize the decrease in the signalsensitivity of the ultrasonic transmission and reception channel whileminimizing the thickness increase of the display device. Further, it ispossible to suppress the occurrence of shadow-mura. Further, it ispossible to shield the electromagnetic interference noise to improve theperformance of the fingerprint sensor 140 and to minimize thedeterioration of the image quality of the electroluminescence displaypanel 110.

In addition, the fingerprint sensor 140 may be attached to the light andEMI shield member 172 by the first adhesive member 150 or the firstadhesive member 150-1.

In addition, the fingerprint sensor 140 may suppress undesireddispersion of ultrasonic waves by the cushion member 168 under the rearside of the light and EMI shield member 172.

The heat dissipation member 164, which may be included in variousembodiments of the present disclosure, may be grounded. The light andEMI shield member 172 and the heat dissipation member 164, which may beincluded in the various embodiments of the present disclosure, may berespectively grounded. The heat dissipation member 164, which may beincluded in various embodiments of the present disclosure, may beelectrically connected to the light and EMI shield member 172. However,the present disclosure is not limited thereto, and it is possible thatthe EMI shield member 170 and the light-shield member 162 areelectrically connected to each other.

According to the above-described configuration, when the heatdissipation member 164 and the light and EMI shield member 172 may beelectrically connected to each other, the potential difference may notbe generated between the heat dissipation member 164 and the light andEMI shield member 172 when they are grounded. Therefore, the parasiticcapacitance can be reduced. In addition, unnecessary noise signals canbe grounded.

In addition, referring to FIG. 27, the light and EMI shield member 172and the heat dissipation member 164 are illustrated as being grounded,but the present disclosure is not limited thereto, and in variousembodiments. For example, it is also possible that the members havingshielding ability and the members having heat-sinking ability with aconductivity of the display devices 1600, 1700, 2300, 3000, 3100 can begrounded to each other.

FIG. 28 to FIG. 35 are cross-sectional views schematically illustratinga cross section A′-A″ corresponding to a fingerprint recognition area ofa display device including an electroluminescence display panel capableof providing a fingerprint recognition function according to the otherembodiments of the present disclosure.

Redundant features of the display devices 2400, 2500, 2600, 2700, 2800,2900, 3000, 3100 according to the other embodiments of the presentdisclosure and the display devices as illustrated in FIG. 1 to FIG. 27according to the other embodiments of the present disclosure may beomitted merely for the sake of convenience of explanation.

The display devices 2400, 2500, 2600, 2700, 2800, 2900, 3000, 3100according to the embodiments of the present disclosure may include alight-shield support substrate 174 disposed between theelectroluminescence display panel 110 and the fingerprint sensor 140.

The light-shield support substrate 174 refers to a support substratehaving a visible light-absorbing function configured to perform thefunctions of the light-shielding member 162 and the support substrate160. The light-shield support substrate 174 may be alternatively appliedto which the support substrate 160 and the light-shielding member 162are applied.

The display device according to embodiments of the present disclosuremay include an electroluminescence display panel 110, a fingerprintsensor 140 disposed below the rear side of the electroluminescencedisplay panel 110, and a light-shield support substrate 174, positionedbetween the electroluminescence display panel 110 and the fingerprintsensor 140, configured to absorb external light that is transmittedthrough the electroluminescence display panel 110 and reflected by thefingerprint sensor 140.

The display device according to the embodiments of the presentdisclosure may include an electroluminescence display panel 110comprising a plurality of pixels formed on a flexible substrate having aYoung's modulus of 2.5 GPa to 3.5 GPa, a fingerprint sensor 140 underthe electroluminescence display panel 110, and a light-shield supportsubstrate 174, positioned between the electroluminescence display panel110 and the fingerprint sensor 140, configured to absorb at least aportion external light pass through the electroluminescence displaypanel 110, and configured to reduce a flatness degradation of theelectroluminescence display panel 110 due to a stress exerted by anadhesive member that bonds the fingerprint sensor 140.

According to the above-described configuration, alternative embodimentshaving the light-shield support substrate 174 may be embodied tosubstitute the embodiments including the support substrate 160 and thelight-shielding member 162, thereby reducing the manufacturing processand the manufacturing cost.

The light-shield support substrate 174 can improve the flatness of theelectroluminescence display panel 110. The light-shield supportsubstrate 174 may be, for example, light absorbing polyethyleneterephthalate (PET). In other words, the Young's modulus of theexemplary light-shield support substrate 174 may be approximately 2.5GPa to 3.5 GPa. However, the present disclosure is not limited thereto.For example, when the light-shield support substrate 174 is polyethyleneterephthalate, the thickness may be 50 μm to 200 μm. In addition, sincethe light-shield support substrate 174 may be configured to perform thesupport function and the light-shielding function simultaneously.Accordingly, the thickness of the support substrate 160 according tosome embodiments may be thicker. However, the present disclosure is notlimited thereto.

The light-shield support substrate 174 may be converted into atransparent or opaque state. That is, the light-shield support substrate174 may include a material whose optical light-shielding property orvisible light transmittance is variable under specific conditions.However, the present disclosure is not limited thereto.

When the transparency of the light-shield support substrate 174 can bevaried, a transparent state can be utilized during the manufacturingprocess.

For example, at the time of manufacturing the electroluminescencedisplay panel 110, an inspection for various defects such as wiringfailure of the electroluminescence display panel 110 can be processed,if the light-shield support substrate 174 is in a transparent state whenthe light-shield support substrate 174 is bonded to theelectroluminescence display panel 110.

When the transparency of the light-shield support substrate 174 can bevaried, the opaque state can be utilized after the manufacturingprocess.

For example, the light-shield support substrate 174 may become opaqueafter the inspection is completed. Therefore, after the defectinspection, the light-shield support substrate 174 can have alight-shielding characteristic. Thus, it can function as alight-shielding member.

The light-shield support substrate 174 may be configured to include atemperature-reactive or photo-reactive material.

That is, the light-shield support substrate 174 may include atemperature-reactive material, and the light-shield support substrate174 may be heat-treated at a predetermined threshold temperature or moreto change the visible light absorption rate. For example, thethermo-chromatic material included in the light-shield support substrate174 can vary in visible light absorption rate when heated above thepredetermined threshold temperature, thereby changing the color fromtransparent to opaque. The light-shield support substrate 174 may have avisible light absorption rate of 80% or more. However, the presentdisclosure is not limited thereto.

For example, the photo-chromatic material included in the light-shieldsupport substrate 174 can be turned from transparent to black whenexposed to light of a particular wavelength. The light-shield supportsubstrate 174 may have a visible light absorption rate of 80% or more.However, the present disclosure is not limited thereto.

According to the above-described configuration, the thickness increaseof the display device can be minimized, the degradation in signalsensitivity of the ultrasonic transmission and reception channel can beminimized, the generation of shadow-mura can be suppressed, and theflatness of the electroluminescence display panel 110 can be maintainedby using the light-shield support substrate 174.

In addition, the fingerprint sensor 140 can suppress undesired diffusionof ultrasonic waves by the cushion member 168 disposed under the rearside of the light and EMI shield member 172.

FIG. 36 is a cross-sectional view schematically illustrating a crosssection A′-A″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function according to the otherembodiment of the present disclosure.

Redundant features of the display device 3200 according to the otherembodiment of the present disclosure and the display devices asillustrated in FIG. 1 to FIG. 35 according to the other embodiments ofthe present disclosure may be omitted merely for the sake of convenienceof explanation.

The display device 3200 according to the other embodiment of the presentdisclosure may include the light-shield support substrate 174 disposedunder the rear side of the electroluminescence display panel 110 and theEMI shield member 170-1 disposed under the rear side of the light-shieldsupport substrate 174.

The EMI shield member 170-1 may be configured to shield the fingerprintsensor 140 by overlapping with the fingerprint sensor 140. That is, theEMI shield member 170-1 may be configured to cover at least thefingerprint sensor 140. The EMI shield member 170-1 may be configured tohave a light-shield ability.

In addition, the heat dissipation member 154 may be arranged under therear side of the light-shield support substrate 174 to cover the outerperiphery of the EMI shield member 170-1. That is, the EMI shield member170-1 may be configured to overlap the opening of the cushion member 168to shield the rear side of the electroluminescence display panel 110corresponding to the area where the fingerprint sensor 140 is disposed.Further, the cushion member 168 may be formed of a light-shielding foamtape. Further, the rear side of the electroluminescence display panel110 may be completely shielded, and at least the fingerprint recognitionarea FDA can be shielded.

According to the above-described configuration, the image qualitydegradation, for example, shadow-mura due to external light can besuppressed by the light-shielding member 162-1 and the cushion member168.

In other words, the cushion member 168 may be configured to cover aportion of the outer periphery of the heat dissipation member 164.

According to the above-described configuration, the light-shield supportsubstrate 174 between the EMI shield member 170-1 and theelectroluminescence display panel 110 can suppress image qualitydeterioration due to external light caused by the EMI shield member170-1. For example, shadow-mura can be suppressed. In addition, heatgenerated from the fingerprint sensor 140 can be effectively dissipated.According to the above-described configuration, the EMI shield member170-1 and the cushion member 168 can suppress the image qualitydegradation caused by external light. In the above-describedconfiguration, when the EMI shield member 170-1 shields at least thefingerprint sensor 140, most of the electromagnetic interference noisecan be suppressed.

FIG. 37 is a conceptual diagram schematically illustrating a displaydevice capable of providing a fingerprint recognition function, apressure sensing function, and a speaker function according to the otherembodiment of the present disclosure.

Redundant features of the display device 3300 according to the otherembodiment of the present disclosure and the display device 100according to an embodiment of the present disclosure may be omittedmerely for the sake of convenience of explanation.

Referring to FIG. 37, a display device 3300 according to the otherembodiment of the present disclosure will be described.

The display device 3300 according to the other embodiment of the presentdisclosure may include an electroluminescence display panel 110 and acase supporting the electroluminescence display panel 110.

The display area of the electroluminescence display panel 110 of thedisplay device 3300 can be maximized by removing the conventionalspeakers 12, 13.

The display device 3300 according to the other embodiment of the presentdisclosure may include at least one speaker capable of outputting soundthrough the electroluminescence display panel 110. For example, a firstspeaker SPK1 and a second speaker SPK2 are disposed under the rear sideof the electroluminescence display panel 110. Accordingly, at least onespeaker can be integrated with the electroluminescence display panel110.

The fingerprint recognition area FDA may be configured to recognizefingerprint recognition and the pressure of the user's finger.

FIG. 38 is a plan view schematically illustrating an electroluminescencedisplay panel of a display device capable of providing a fingerprintrecognition function, a pressure sensing function, and a speakerfunction according to the other embodiment of the present disclosure.

Redundant features of the display device 3300 according to the otherembodiment of the present disclosure and the display device 100according to an embodiment of the present disclosure may be omittedmerely for the sake of convenience of explanation.

Referring to FIG. 38, an electroluminescence display panel 110 of thedisplay device 3300 according to the other embodiment of the presentdisclosure will be described.

Ultrasonic waves generated from the fingerprint sensor can betransmitted to the fingerprint recognition area FDA set in the displayarea AA to enable fingerprint recognition. The degree of pressure of theuser's finger can be recognized. Thus, it is also possible todistinguish the degrees of the pressure. Although only one fingerprintrecognition area is illustrated in FIG. 38, the present disclosure isnot limited thereto. In addition, a plurality of fingerprint recognitionareas can be arranged.

For example, the two fingerprint recognition areas can be arrangedsymmetrically with respect to the center of the display area. Accordingto the above-described arrangement, even if the display area AA isrotated 180 degrees, the same user experience can be provided that canperform the fingerprint recognition function at substantially the sameposition with respect to the user. That is, the same user experience canbe provided regardless of which direction the user holds the displaydevice.

In the speaker areas SPK1 and SPK2 set in the display area AA, the soundgenerated from the film-type speaker disposed under the rear side of theelectroluminescence display panel 110 is transmitted to the front sideof the electroluminescence display panel 110 to output sound.

For example, two speaker areas can be arranged symmetrically withrespect to the center of the pixel area. According to theabove-described configuration, even if the display area AA rotates 180degrees, an user experience can be provided with an acoustic experienceat substantially the same position.

For example, a plurality of speaker areas may be arranged within adisplay area at specific distances to output multi-channel sound.

FIG. 39A is a cross-sectional view schematically illustrating a crosssection B′-B″ corresponding to a fingerprint recognition area of adisplay device including an electroluminescence display panel capable ofproviding a fingerprint recognition function, a pressure sensingfunction, and a speaker function according to the other embodiment ofthe present disclosure.

Redundant features of the display device 3300A according to the otherembodiment of the present disclosure and the display devices asillustrated in FIG. 1 to FIG. 36 according to the other embodiments ofthe present disclosure may be omitted merely for the sake of convenienceof explanation.

The electroluminescence display panel 110 of the display device 3300Aaccording to the other embodiment of the present disclosure may includea substrate, configured to act as an ultrasonic transmission andreception channel of a fingerprint sensor 140, a transistor on thesubstrate, an electroluminescence element on the transistor, and anencapsulation unit on the electroluminescence element.

The display device 3300A according to the other embodiment of thepresent disclosure may include a fingerprint sensor 140 under the rearside of the electroluminescence display panel 110 and a pressure sensor190 under the rear side of the fingerprint sensor 140. The fingerprintsensor 140 may be configured to transmit ultrasonic waves to afingerprint and receive the reflected ultrasonic waves to recognizefingerprints touched on the fingerprint recognition area FDA.

The display device 3300A according to the other embodiment of thepresent disclosure may include a display area AA including a fingerprintrecognition area FDA, a plurality of pixels PXL disposed on a substrateof an electroluminescence display panel 110, an ultrasonic fingerprintsensor 140 under a rear side of the substrate corresponding to thefingerprint recognition area FDA, and a pressure sensor 190 under therear side of the fingerprint sensor 140. In addition, when the pressuresensor 190 is disposed under the rear side of the fingerprint sensor140, the user's finger pressure can be detected more accurately in thefingerprint recognition area FDA. If the pressure sensor 190 does notoverlap with the fingerprint sensor 140 or overlaps at least a portionof the fingerprint sensor 140, the pressure sensing sensitivity may bereduced during fingerprint recognition. If the pressure sensor 190 doesnot overlap with the fingerprint sensor 140, at least a portion isoverlapped, or pressure is applied to an area other than the fingerprintrecognition area FDA, the fingerprint sensor 140 may be operatedunintentionally.

A display device 3300A according to the other embodiment of the presentdisclosure may include an electroluminescence display panel 110configured to display an image, a fingerprint sensor 140 under the rearsurface of the electroluminescence display panel 110, and a pressuresensor 190 under the rear side of the fingerprint sensor 140 andconfigured to detect a pressure that can be applied to theelectroluminescent display panel 110. Further, the front surface of thefingerprint sensor 140 may be fixed to the rear surface of theelectroluminescence display panel 110 by the first adhesive member 150.Furthermore, the rear surface of the fingerprint sensor 140 may be fixedto the pressure sensor 190 by the fourth adhesive member 156.

A display device 3300 according to the other embodiment of the presentdisclosure may include a plurality of pixels on a flexible substrate, acushion member, under the flexible substrate, having at least oneopening, at least one pressure sensor 190, under the cushion member 168,configured to receive pressure through a periphery of the at least oneopening, and a fingerprint sensor 140 between the flexible substrate andthe at least one pressure sensor 190. At least one pressure sensor 190may be configured to receive at least a portion of the pressure throughthe corresponding at least one fingerprint sensor 140. At least onepressure sensor 190 may be configured to receive at least anotherportion of the pressure through a corresponding cushion member 168. Inaddition, when the pressure is transmitted only through the fingerprintsensor 140, the stress applied to the fingerprint sensor 140 may beincreased. When the pressure is transmitted only through the cushionmember 168, the pressure may be absorbed by the cushion member 168, andthe pressure sensing precision may be reduced. The pressure sensor 190may be realized by a resistance sensing type or a capacitance sensingtype. However, the present disclosure is not limited thereto.

The light-shield support substrate 174 may be located between thesubstrate of the electroluminescence display panel 110 and theultrasonic fingerprint sensor 140. However, as described above, it isalso possible to implement using alternative configurations disclosed inthe embodiments of the present disclosure. For example, the light-shieldsupport substrate 174 may be substituted with the support substrate 160of other embodiments. It is also possible that the light-shield member162 is further disposed under the rear surface of the support substrate160.

The cushion member 168 may be disposed under the rear side of thelight-shield support substrate 174 and may be configured to surround thefingerprint sensor 140 with an opening formed therein. The thickness ofthe cushion member 168 may be configured to be substantially the same asthe thickness of the fingerprint sensor 140 or may be configured to havea particular thickness that can minimize the step difference. However,the present disclosure is limited thereto. For example, if thefingerprint sensor 140 and the cushion member 168 have substantially thesame thickness, the step difference between the fingerprint sensor 140and the pressure sensor 190 can be reduced. Therefore, it may be easierfor the pressure sensor 190 to be attached under the fingerprint sensor140. The cushion member 168 may be configured to surround thefingerprint sensor 140 to absorb the ultrasonic output from thefingerprint sensor 140. The cushion member 168 may be disposed betweenthe electroluminescence display panel 110 and the pressure sensor 190.Accordingly, it can be configured to transmit a portion of the pressurethat can be transmitted from the electroluminescence display panel 110to the pressure sensor 190.

The pressure sensor 190 may be configured to overlap at least a portionof the cushion member 168 and at least a portion of the fingerprintsensor 140. The area of the pressure sensor 190 may be larger than thearea of the fingerprint sensor 140. The pressure sensor 190 and thefingerprint sensor 140 may be arranged to overlap with each other. Thepressure sensor 190 may be disposed under the rear surface of thefingerprint sensor 140. In addition, it is preferable that the pressuresensor 190 is disposed under the rear surface of the fingerprint sensor140 because the pressure sensor 190 does not sense the shape of aprecise fingerprint such as a fingerprint. If the fingerprint sensor 140is disposed under the pressure sensor 190, the sensitivity of theultrasonic signal may be reduced and the fingerprint recognition rate orthe fingerprint-sensing rate may be lowered.

The fourth adhesive member 156 may be configured to fix the fingerprintsensor 140, the pressure sensor 190, and the cushion member 168 at thesame time. The pressure sensor 190 and the fingerprint sensor 140 can beadhered by the fourth adhesive member 156. The cushion member 168 andthe pressure sensor 190 can be adhered by the fourth adhesive member156. The pressure sensor 190 may be configured to be wider than theopening of the cushion member 168 and overlap with a portion of thecushion member 168 adjacent to the opening while overlapping with thefingerprint sensor 140.

The first adhesive member 150 and the fourth adhesive member 156 may bemade of the same material. The first adhesive member 150 and the fourthadhesive member 156 may be made of materials different from each other.Since the first adhesive member 150 is a path for transmitting andreceiving ultrasonic waves to and from the electroluminescence displaypanel 110, the Young's modulus and thickness of the first adhesivemember 150 should be determined in consideration of ultrasonictransmission and reception characteristics. Since the fourth adhesivemember 156 requires a Young's modulus capable of transmitting pressureto the pressure sensor 190, the Young's modulus and the thickness of thefirst adhesive member 152 may be less restrictive than those of thefirst adhesive member 152.

As the Young's modulus of the fourth adhesive member 156 is low or thethickness is thicker, the pressure transfer characteristics may bereduced. On the other hand, as the Young's modulus of the fourthadhesive member 156 is high or the thickness is thinner, the pressuretransfer characteristics can be improved. However, the fourth adhesivemember 156 may take into account not only the pressure transmissioncharacteristic but also the shock absorption characteristic transmittedto the fingerprint sensor 140.

For example, when the Young's modulus of the fourth adhesive member 156is low, when the impact is transmitted to the fingerprint sensor 140through the electroluminescence display panel 110, the fingerprintsensor 140 may be damaged. In addition, the fingerprint sensor 140 maybe made of a material having a high Young's modulus value suitable forgenerating ultrasonic waves for fingerprint recognition. In this case,it may be vulnerable to breakage. When the Young's modulus of the fourthadhesive member 156 is relatively lower than the Young's modulus of thefirst adhesive member 152, the fourth adhesive member 156 may absorb theimpact and protect the fingerprint sensor 140. When the thickness of thefourth adhesive member 156 is thicker than the thickness of the firstadhesive member 152, the fourth adhesive member 156 may absorb theimpact and protect the fingerprint sensor 140.

The fingerprint sensor 140 may be configured to turn on the fingerprintsensor 140 when the pressure input through the pressure sensor 190 isequal to or greater than a predetermined threshold value. That is, thepressure sensor 190 may be configured to control the power of thefingerprint sensor 140. In other words, the power consumption of thefingerprint sensor 140 may be relatively higher than that of thepressure sensor 190. Therefore, the stand-by power or the powerconsumption of the fingerprint sensor 140 can be reduced by using thepressure sensor 190.

FIG. 40A and FIG. 41A are cross-sectional views schematicallyillustrating cross section C′-C″ and D′-D″ corresponding to fingerprintrecognition areas of a display device including an electroluminescencedisplay panel capable of providing a fingerprint recognition function, apressure sensing function, and a speaker function according to the otherembodiment of the present disclosure.

Redundant features of the display device 3300A according to the otherembodiment of the present disclosure and the display devices asillustrated in FIG. 1 to FIG. 39A according to the other embodiments ofthe present disclosure may be omitted merely for the sake of convenienceof explanation.

A display device 3300A according to the other embodiment of the presentdisclosure may include an electroluminescence display panel 110including a display area AA configured to recognize a fingerprint, afingerprint sensor 140 positioned in the fingerprint recognition areaFDA and a film-type speaker 192-1 provided in the first area SPK1 of theelectroluminescence display panel 110. However, the present disclosureis not limited thereto. Further, another film-type speaker 192-2 may beprovided in the second area SPK2 of the electroluminescence displaypanel 110. That is, a plurality of film-type speakers may be provided.The light-shield support substrate 174 may be positioned theelectroluminescence display panel 110 and the fingerprint sensor 140 andmay be positioned between the electroluminescence display panel 110 andthe film-type speakers 192-1, 192-2.

The electroluminescence display panel 110 of the display device 3300Amay include a substrate configured to be an output path of theultrasonic transmission and reception channel of the fingerprint sensor140 and the film type speakers 192-1, 192-2, a transistor on thesubstrate, an electroluminescence element on the transistor, and anencapsulation on the electroluminescent element. Further, the substrateof the electroluminescence display panel 110 may be configured to have aflexible characteristic to transmit pressure of the user's finger.

A display device 3300A may include an electroluminescence display panel110 configured to output sound and to display an image, a fingerprintsensor 140 configured to enable fingerprint recognition using anultrasonic method through the electroluminescence display panel 110, anda film type speaker 192-1, 192-2 under the rear side of the fingerprintsensor 140.

As an example, a plurality of film-type speakers 192-1, 192-2 may becomposed of a piezoelectric speaker and may be configured to include anactuator of a piezoelectric element. That is, the film-type speaker maybe a piezo speaker including a piezoelectric element. That is, theaudible frequency vibration output from the speaker may vibrate theelectroluminescence display panel 110 bonded to the film-type speakers192-1 and 192-2, and by the vibration of the electroluminescence displaypanel 110, sound may be provided to the user.

The cushion member 168 may be positioned under the rear side of thelight-shield support substrate 174 and may be configured to surround thefingerprint sensor 140. The cushion member 168 may be positioned betweenthe film-type speaker and the electroluminescence display panel 110, andmay be configured to transmit sound in a band of 20 KHz or less whileabsorbing ultrasonic waves in a band of 10 MHz or more.

At least one film-type speaker of the plurality of film-type speakers192-1, 192-2 may be overlapped with the cushion member 168. At least onefilm-type speaker of the plurality of film-type speakers 192-1, 192-2may be overlapped with the fingerprint sensor 140. In addition, thecushion member 168 may be removed according to the outputcharacteristics of the frequency band of the film-type speaker. Inaddition, the cushion member may be a foam tape, and the cushion membercan relatively absorb the sound of the high frequency band relative tothe low frequency band. Therefore, when the output of the high-frequencyband of the film-type speaker is insufficient, the cushion member of theregion where the corresponding film-type speaker is arranged may beremoved.

The film-type speaker may be configured to output sound in the directiontoward the electroluminescence display panel 110. However, the presentdisclosure is not limited thereto, and it may be configured to outputsound in the opposite direction to the electroluminescence display panel110, or to output sound in both directions.

The plurality of film-type speakers 192-1, 192-2 may be at least two ormore, and each of the film-type speakers may be spaced apart from eachother under the electroluminescence display panel 110.

In some embodiments, at the rear surface of the cushion member, ametallic diaphragm for amplifying the output of the film-type speakermay be provided. The film-type speaker can be configured to output soundthrough a metallic diaphragm and a fingerprint sensor.

In some embodiments, the display device may include a plurality ofpixels on a flexible substrate, a cushion member, under the flexiblesubstrate, including at least one opening, a film-type speaker, underthe cushion member, adhered to the periphery of the at least one openingto output sound, and a fingerprint sensor between the film-type speakerand the flexible substrate. In this case, the film-type speaker (e.g.,piezo speaker) may be configured to transmit sound through thefingerprint sensor.

In some embodiments, a display device may be positioned between afilm-type speaker and a cushion member. Further, a heat dissipationmember configured to dissipate heat of the film-type speaker and thefingerprint sensor may be included.

FIG. 39B, FIG. 40B and FIG. 41B are cross-sectional views schematicallyillustrating cross section B′-B″, C′-C″ and D′-D″ corresponding to afingerprint recognition area of a display device including anelectroluminescence display panel capable of providing a fingerprintrecognition function, a pressure sensing function, and a speakerfunction according to the other embodiment of the present disclosure.

Redundant features of the display device 3300B according to the otherembodiment of the present disclosure and the display devices asillustrated in FIG. 1 to FIG. 39A, FIG. 40A and FIG. 41A, according tothe other embodiments of the present disclosure may be omitted merelyfor the sake of convenience of explanation.

Referring to FIG. 39B, FIG. 40B and FIG. 41B, a display device 3300Baccording to the other embodiment of the present disclosure may includean EMI shield member 170 disposed between an electroluminescence displaypanel 110 and a cushion member 168. Specifically, the EMI shield member170 may be disposed between a light-shield support substrate 174 and thecushion member 168.

The EMI shield member 170 may be made of a conductive material. Forexample, the EMI shield member 170 may comprise metallic particles ormay be a metal foil. The EMI shield member 170 may be coated directly atthe rear side of the light-shield support substrate 174 or may be bondedtogether through a separate bonding member. The EMI shield member 170may be a metal layer, for example, including copper (cu) and may beconfigured to shield external light transmitted through theelectroluminescence display panel 110. In addition, the EMI shieldmember 170 may be a conductive ink. The EMI shield member 170 may becoated or printed directly under the rear side of the light-shieldsupport substrate 174. In addition, the EMI shield member 170 may be athin metal film. The EMI shield member 170 may be deposited on thelight-shield support substrate 174.

Accordingly, when the EMI shield member 170 is formed directly on thelight-shield support substrate 174, since an adhesive member isunnecessary, an additional adhesive member may not be required even ifthe EMI shield member 170 is added. Therefore, it is possible to improvethe image quality of the electroluminescence display panel 110 and thefingerprint recognition sensitivity of the fingerprint sensor 140 whilemaintaining the signal sensitivity of the fingerprint sensor 140.

Referring to FIG. 39B, the EMI shield member 170 may be configured toshield at least a region where the fingerprint sensor 140 and theelectroluminescence display panel 110 are overlapped. For example, theEMI shield member 170 may be configured to shield at least thefingerprint recognition area FDA. However, the present disclosure is notlimited thereto. Further, the EMI shield member 170 may be configured toshield the fingerprint recognition area FDA and at least a portion ofthe display area AA. That is, the EMI shield member 170 may beconfigured to shield at least the electromagnetic interference noisebetween the electroluminescence display panel 110 and the fingerprintsensor 140 by shielding at least the fingerprint recognition area FDA.

In addition, referring to FIG. 40B and FIG. 41B, the EMI shield member170 may be configured to shield at least a region where a plurality offilm-type speakers 192-1 and 192-2 and the electroluminescence displaypanel 110 are overlapped. For example, the EMI shield member 170 may beconfigured to shield at least a first area SPK1 and a second area SPK2of the electroluminescence display panel 110. However, the presentdisclosure is not limited thereto. Further, the EMI shield member 170may be configured to shield the first area SPK1 and the second area SPK2of the electroluminescence display panel 110 and at least a portion ofthe display area AA. That is, the EMI shield member 170 may beconfigured to shield at least the electromagnetic interference noisebetween the electroluminescence display panel 110 and the plurality offilm-type speakers 192-1 and 192-2 by shielding at least the first areaSPK1 and the second area SPK2 of the electroluminescence display panel110.

Therefore, the deterioration in image quality of the electroluminescencedisplay panel 110 due to the electromagnetic interference generated bythe operations of the fingerprint sensor 140 of the ultrasonic type andthe film-type speakers 192-1 and 192-2 which are piezoelectric speakerscan be suppressed, but also, at the same time, the deterioration infingerprint recognition sensitivity of the fingerprint sensor 140 due tothe electromagnetic interference of the electroluminescence displaypanel 110 can be suppressed.

FIG. 39C, FIG. 40C and FIG. 41C are cross-sectional views schematicallyillustrating cross section B′-B″, C′-C″ and D′-D″ corresponding to afingerprint recognition area of a display device including anelectroluminescence display panel capable of providing a fingerprintrecognition function, a pressure sensing function, and a speakerfunction according to the other embodiment of the present disclosure.

Redundant features of the display device 3300C according to the otherembodiment of the present disclosure and the display devices asillustrated in FIG. 1 to FIG. 39A, FIG. 40A and FIG. 41A, according tothe other embodiments of the present disclosure may be omitted merelyfor the sake of convenience of explanation.

Referring to FIG. 39C, FIG. 40C and FIG. 41C, the display device 3300Caccording to the other embodiment of the present disclosure may beconfigured to include a heat dissipation member 164 disposed under arear surface of the cushion member 168.

The heat dissipation member 164 may be configured to surround thefingerprint sensor 140 and overlap a portion of the display area AA toperform the function of a heat sink for the electroluminescence displaypanel 110. For example, the heat dissipation member 164 may be disposedto correspond to an area of the cushion member 168 under the rearsurface of the cushion member 168.

The heat dissipation member 164 may be made of a material having a highthermal conductivity. For example, the heat dissipation member 164 maybe made of a material such as metal, graphite, and/or graphene. Forexample, the thickness of the heat dissipation member 164 may be 50 μmto 100 μm. However, the present disclosure is not limited thereto

According to the above-described configuration, the temperaturedeviation between the fingerprint sensor 140 and periphery of thefingerprint sensor 140 can be reduced by the heat dissipation member164. Therefore, it is possible to reduce the occurrence of imageretention due to the attachment of the fingerprint sensor 140.

In addition, when the heat dissipation member 164 is a conductivematerial, the heat dissipation member 164 can be electrically grounded.However, the present disclosure is not limited thereto.

Referring to FIG. 40C and FIG. 41C, the heat dissipation member 164 maybe disposed between the film-type speakers 192-1 and 192-2 and thecushion member 168. Accordingly, the heat dissipation member 164 may bedisposed between the electroluminescence display panel 110 and the filmtype speakers 192-1 and 192-2. The temperature of an area where the filmtype speakers 192-1 and 192-2 are attached may increase depending on theoutput of the film type speakers 192-1 and 192-2. If a temperaturedifference occurs between the area where the film type speakers 192-1and 192-2 are attached and the area where the film type speakers 192-1and 192-2 are not attached, a temperature deviation of theelectroluminescence display panel 110 may occur and a residual image mayappear on the displayed image. That is, the heat dissipation member 164can reduce the temperature deviation.

FIG. 42 is a cross-sectional view illustrating a stack structure of anexemplary electroluminescence display panel which can be applied to across-section A′-A″ of a display device according to the otherembodiment of the present disclosure.

Redundant features of the display device 3400 according to the otherembodiment of the present disclosure and the display device 100according to an embodiment of the present disclosure may be omittedmerely for the sake of convenience of explanation.

The electroluminescence display panel 210 of the display device 3400according to the other embodiment of the present disclosure may beconfigured to include an integrated touch panel 220. The integratedtouch panel 220 may be formed on the encapsulation unit 128, 130, 132.

The integrated touch panel 220 may be formed by depositing electrodelayers 222, 226 and insulating layers 224, 228 on the encapsulation unit128, 130, 132 during the manufacturing process of theelectroluminescence display panel 210. That is, the integrated touchpanel 220 does not require an additional substrate for forming aseparate touch panel. Thus, the integrated touch panel 220 may be formedon the encapsulation unit 128, 130, 132 of the electroluminescencedisplay panel 210, thereby minimizing the thickness increase and thesignal sensitivity degradation of the transmitting and receiving channelfor the ultrasonic fingerprint recognition.

By forming the integrated touch panel 220, an unnecessary adhesionprocess and an unnecessary adhesive member for bonding the conventionaltouch panel and the electroluminescence display panel can be eliminated.Accordingly, it is possible to remove an adhesive member having a lowYoung's modulus, which may deteriorate ultrasonic transmission andreception sensitivity, from being positioned between the integratedtouch panel 220 and the electroluminescence display panel 210.

Each layer of the integrated touch panel 220 of the electroluminescencedisplay panel 210 according to the other embodiment of the presentdisclosure may be formed of a material having a high Young's modulusvalue, for example, the integrated touch panel 220 may be made of ametal material and an inorganic thin film. Thus, the thickness of theultrasonic transmission and reception channel 220 can be reduced.Therefore, the deterioration of the signal sensitivity of the ultrasonictransmission and reception channel can be minimized. A touch bufferlayer 212 may be disposed between the encapsulation unit 132 and theintegrated touch panel 220. When the integrated touch panel 220 isformed on the encapsulation unit 128, 130, 132, the touch buffer layer212 may protect the pad portion formed in the non-display area NA of theelectroluminescence display panel 210 from being corroded during anetching process. The thickness of the touch buffer layer 212 may besmaller than the thickness of the second inorganic encapsulation layer132. The touch buffer layer 212 may be formed of an inorganic film suchas silicon nitride (SiNx), silicon oxide (SiOx), or silicon oxynitride(SiON). The thickness of the touch buffer layer 212 may be 0.1 μm to 0.4μm. However, the present disclosure is not limited thereto, and thetouch buffer layer 212 may be removed.

The first touch electrode layer 222 of the integrated touch panel 220may be formed of a metallic conductive material having a low electricalresistance. However, the present disclosure is not limited thereto. Thefirst touch electrode layer 222 may have a single-layer structure or amulti-layer structure. The first touch electrode layer 222 may be formedin the form of a metal-mesh that has a width narrower than the width ofthe bank 124. The first touch electrode layer 222 may configure aportion of a driving electrode, a sensing electrode, and/or a bridgeelectrode of the integrated touch panel 220. For example, the thicknessof the first touch electrode layer 222 may be 0.2 μm to 0.5 μm. However,the present disclosure is not limited thereto.

The first touch insulation layer 224 may be disposed on the first touchelectrode layer 222. The first touch insulation layer 224 may insulatethe first touch electrode layer 222 from the second touch electrodelayer 226. The first touch insulation layer 224 may be formed of aninorganic film such as silicon nitride (SiNx), silicon oxide (SiOx), orsilicon oxynitride (SiON). For example, the thickness of the first touchinsulation layer 224 may be 0.2 μm to 0.5 μm. However, the presentdisclosure is not limited thereto.

The second touch electrode layer 226 may be disposed on the first touchinsulation layer 224. The second touch electrode layer 226 may bepreferably made of a metallic conductive material having a lowelectrical resistance. The second touch electrode layer 226 may have asingle-layer structure or a multi-layer structure. The second touchelectrode layer 226 may be formed in the form of a metal-mesh that has awidth narrower than the width of the bank 124. The second touchelectrode layer 226 may configure another portion of the drivingelectrode, the sensing electrode, and/or the bridge electrode of theintegrated touch panel 220. For example, the thickness of the secondtouch electrode layer 226 may be 0.2 μm to 0.5 μm. However, the presentdisclosure is not limited thereto.

A portion of the first touch electrode layer 222 and a portion of thesecond touch electrode layer 226 are electrically connected to eachother through a contact hole formed in the first touch insulation layer224 to form a bridge portion.

The second touch insulation layer 228 may be disposed on the secondtouch electrode layer 226. The second touch insulation layer 228 may beconfigured to cover the second touch electrode layer 226. The secondtouch insulation layer 228 may be formed of an inorganic film such assilicon nitride (SiNx), silicon oxide (SiOx), or silicon oxynitride(SiON), or an organic film such as an acryl material, epoxy material,Parylene-C, Parylene-N, or Parylene-F, or a siloxane-based organic film.For example, the thickness of the second touch insulation layer 228 maybe 0.2 μm to 3 μm. However, the present disclosure is not limitedthereto.

The second touch insulation layer 228 may prevent corrosion of thesecond touch electrode layer 226 or may insulate the second touchelectrode layer 226. However, the present disclosure is not limited tothe second touch insulation layer 228. In some cases, the second touchinsulation layer 228 may be omitted.

The integrated touch panel 220 of the electroluminescence display panel210 according to the other embodiment of the present disclosure may beformed of a capacitive touch panel. The integrated touch panel 220 mayinclude a first touch electrode layer 222 on the encapsulation unit 132,a first touch insulation layer 224 on the first touch electrode layer222, a second touch electrode 226 on the first touch insulation layer224, and a second touch insulation layer 228 on the second touchelectrode 226. Each of the layers configuring the integrated touch panel220 may be made of a material having a Young's modulus of at least 1 GPaor more. In addition, the integrated touch panel 220 may have athickness of 0.8 μm to 4.5 μm to minimize the signal sensitivityreduction of the ultrasonic transmission and reception channel of thefingerprint sensor.

The polarizer 242 may be further included on the integrated touch panel220. The polarizer 242 may be configured to absorb ambient lightreflection. A polarizer adhesive member 240 capable of bonding thepolarizer 242 and the integrated touch panel 220 may be applied betweenthe polarizer 242 and the integrated touch panel 220. It is preferablethat the polarizer adhesive member 240 is made of an adhesive memberhaving a high Young's modulus in consideration of ultrasonictransmission and reception characteristics. However, the presentdisclosure is not limited thereto. In addition, it is possible that thepolarizer 242 and the polarizer adhesive member 240 are omitted.

A cover 246 may be further included on the polarizer 242. The cover 246may be configured to protect the electroluminescence display panel 210.A cover adhesive member 244 capable of bonding the cover 264 and thepolarizer 242 may be applied between the cover 246 and the polarizer242. The cover adhesive member 244 is preferably made of an adhesivemember having a high Young's modulus in consideration of ultrasonictransmission and reception characteristics. However, the presentdisclosure is not limited thereto. In addition, it is possible that thecover 246 and the cover adhesive member 244 are omitted. Further, theYoung's modulus of the cover may be 50 GPa or more.

The controller of the fingerprint sensor 140 may generate ultrasonicwaves of a suitable frequency to pass through the cover 246 on the frontsurface of the electroluminescence display panel 110. For example,ultrasonic waves having a frequency of 10 MHz to 15 MHz can be generatedand then transmitted and received through the sensor electrode 144.

In some embodiments, it is also possible to provide various functionallayers on the touch panel, such as a protective film, an antistaticfilm, a polarizing film, an ambient light absorbing film, a protectiveglass, and the like.

A means implemented to be attachable to the rear surface of theelectroluminescence display panel according to various embodiments ofthe present disclosure can be referred to an arrangement means of thepresent disclosure. For example, various adhesive members, alight-shield member, a support substrate, a heat dissipation member, acushion member, an EMI shield member, a light and EMI shield member, alight-shield support substrate, a pressure sensor and the like can bereferred to an arrangement means.

What is claimed is:
 1. A display device comprising: a substrateincluding a first surface and a second surface that is under the firstsurface; a transistor on the first surface of the substrate; anelectroluminescence element on the transistor; an encapsulation unit onthe electroluminescence element; and a fingerprint sensor under thesecond surface of the substrate; wherein a portion of the substrate, aportion of the transistor, a portion of the electroluminescence element,and a portion of the encapsulation unit that overlap the fingerprintsensor are an ultrasonic transmission and reception channel on thefingerprint sensor, wherein the encapsulation unit within the ultrasonictransmission and reception channel comprises a first inorganicencapsulation layer, an organic encapsulation layer on the firstinorganic encapsulation layer, and a second inorganic encapsulationlayer on the organic encapsulation layer, wherein a Young's modulus ofthe first inorganic encapsulation layer and a Young's modulus of thesecond inorganic encapsulation layer are greater than a Young's modulusof the organic encapsulation layer.
 2. The display device of claim 1,wherein the ultrasonic transmission and reception channel lacks an airgap.
 3. The display device of claim 1, further comprising: an adhesivethat attaches the fingerprint sensor to the display device; and whereinthe adhesive comprises a thickness in a range from 5 μm to 15 μm.
 4. Thedisplay device of claim 3, wherein the adhesive comprises a cured epoxyhaving a Young's modulus of 2 Gpa to 4 Gpa responsive to the fingerprintsensor being an ultrasonic finger print sensor.
 5. The display device ofclaim 3, wherein the adhesive comprises a defoamed resin.
 6. The displaydevice of claim 3, wherein the adhesive is a film-type adhesive having awidth that is wider than a width of the fingerprint sensor; and whereinthe adhesive comprises a Young's modulus in a range of 0.02 MPa to 0.4MPa.
 7. The display device of claim 1, wherein the Young's modulus ofthe first inorganic encapsulation layer and the Young's modulus of thesecond inorganic encapsulation layer is in a range from 70 GPa to 300GPa.
 8. The display device of claim 1, wherein the organic encapsulationlayer is thicker than the first inorganic encapsulation layer and thesecond inorganic encapsulation layer, wherein a thickness of the organicencapsulation layer is in a range of 3 μm to 10 μm.
 9. A display devicecomprising: a substrate including a first surface and a second surfacethat is under the first surface; an ultrasonic fingerprint sensordisposed on a portion of the second surface of the substrate; anadhesive between the substrate and the ultrasonic fingerprint sensor,the adhesive in direct contact with the ultrasonic fingerprint sensor; atransistor including an insulating unit, the transistor on the firstsurface of the substrate, and wherein an air gap is not present betweenthe transistor and the substrate; a planarization layer directly on thetransistor; an electroluminescence element directly on the planarizationlayer; and an encapsulation unit including a plurality of encapsulationlayers, the encapsulation unit directly on the electroluminescenceelement, and wherein the plurality of encapsulation layers lack an airgap between the plurality of encapsulation layers, wherein a Young'smodulus of the insulating unit of the transistor is greater than aYoung's modulus of the planarization layer.
 10. The display device ofclaim 9, wherein the substrate is flexible and comprises a thickness ina range of 3 μm to 30 μm.
 11. The display device of claim 9, furthercomprising: a support substrate between the substrate and the ultrasonicfingerprint sensor, the support substrate reducing deformation of thedisplay device while the fingerprint sensor is adhered to the displaydevice, and wherein the support substrate is transparent or opaque. 12.The display device of claim 11, further comprising: a light-shield layerbetween the support substrate and the ultrasonic fingerprint sensor, thelight-shield layer shielding the transistor from light external to thedisplay device.
 13. The display device of claim 12, wherein thelight-shield layer is thinner than the support substrate.
 14. Thedisplay device of claim 13, wherein the light-shield layer comprises athickness in a range of 8 μm to 20 μm or in a range of 8 μm to 25 μm.15. A display device comprising: a display panel comprising a pluralityof components; an ultrasonic fingerprint sensor under a portion of thedisplay panel; and a first adhesive that attaches the ultrasonicfingerprint sensor directly to the display panel; wherein each of theplurality of components in a portion of the display panel thathorizontally overlaps the ultrasonic fingerprint sensor is in contactwith at least one other component from the plurality of components ofthe display panel, wherein the plurality of components comprises: asubstrate; a transistor on the substrate, the transistor including aninsulation unit comprising a first inorganic insulation layer and asecond inorganic insulation layer on the first inorganic insulationlayer; and a planarization layer on the transistor; wherein a Young'smodulus of the first inorganic insulation layer and a Young's modulus ofthe second inorganic insulation layer are greater than a Young's modulusof the planarization layer.
 16. The display device of claim 15, whereinthe ultrasonic fingerprint sensor is configured to generate a signalhaving a frequency between 10 MHz to 15 MHz.
 17. The display device ofclaim 15, wherein the plurality of components further comprises: asecond adhesive between the substrate and a support substrate, whereinthe second adhesive comprises a Young's modulus in a range of 0.02 MPato 0.4 MPa, and wherein a thickness of the second adhesive is in a rangeof 5 μm to 15 μm.
 18. The display device of claim 15, furthercomprising: a cushion member surrounding the ultrasonic fingerprintsensor without horizontally overlapping the ultrasonic fingerprintsensor.
 19. The display device of claim 15, further comprising: anelectromagnetic interference (EMI) shielding layer between the substrateand the ultrasonic fingerprint sensor, the EMI shielding layer shieldingthe fingerprint sensor from EMI interference.